Press Release



Proposed abolition of the corroboration rules for sexual offences


Following is an information paper which sets out the background to the Administration's proposal to abolish the corroboration rules for sexual offences:


Corroboration is evidence which confirms the accuracy of other evidence in a material particular. In criminal cases, it must confirm or tend to confirm the guilt of the accused.

Two issues arise in respect of corroboration. The first issue is what types of cases require corroboration. The second issue is what kinds of evidence constitute corroboration.


As a general rule, evidence given against a defendant does not need to be corroborated. A defendant can generally be convicted on the uncorroborated evidence of a single credible witness, provided that the judge or jury is satisfied, beyond reasonable doubt, of the defendant's guilt. However, in certain cases, corroboration rules have been established. The corroboration rules were formulated in the interests of the accused, with the aim of avoiding wrongful convictions in three types of cases, namely, (i) the evidence of accomplices; (ii) the evidence of the complainant in sexual offences; (iii) the evidence of children.

In Hong Kong the corroboration rules were abolished in respect of the evidence of accomplices and children in 1994 and 1995 respectively. The present paper therefore focuses on the remaining application of the corroboration rules to the evidence of complainants in sexual offences.

Elements of the corroboration rules

The corroboration rules apply in two ways. In some cases, corroboration is required by law. This means that a defendant cannot be convicted if there is no corroboration. Examples of this requirement can be found in the following sections of the Crimes Ordinance (Cap. 200) -

* s. 119 procuring a person by threats or intimidation to do an unlawful sexual act

* s. 120 procuring a person by false pretences or false representations to do an unlawful sexual act

* s. 121 administering drugs to another person to obtain or facilitate an unlawful sexual act

* s. 130 exercising control or direction over another person for purposes of unlawful sexual intercourse or prostitution

* s. 131 procuring a person to become a prostitute

* s. 132 procuring a girl under 21 to have unlawful sexual intercourse

* s. 133 procuring a woman who is a defective to have unlawful sexual intercourse.

In some other cases, a corroboration warning must be given: the judge must remind himself or warn the jury of the danger of convicting on uncorroborated evidence. Cases in this category include rape and indecent assault. Provided that a warning is given, a defendant can be convicted even if there is no corroboration.


Traditionally, the evidence of victims of sexual offences has been regarded as peculiarly susceptible to fantasy or fabrication, perhaps motivated by frustration, spite or remorse. The corroboration rules were intended to reduce the danger arising from the fact that complaints of sexual offences are easy to make but difficult to refute. There is said to be an additional danger that sympathy for the complainant as a witness may prevent the jury or judge from evaluating the evidence dispassionately.


The corroboration rules have been criticized on several grounds which are stated below.

Discrimination against victims of sexual offences

It has been argued that the corroboration rules work particularly to the disadvantage of victims of sexual offences. Although the rules do not differentiate between the gender of the victims, nevertheless the majority of victims of sexual offences are female. It has been suggested that the reasons for the existence of the corroboration rules in sexual cases are insulting to women in general, and to complainants in particular, when those reasons are not objectively based, and the rules are applied irrespective of the particular facts of the case. It has also been argued that the prospect of the recitation by the judge of the corroboration warning, and its possible effect upon the jury, operates as a deterrent to the prosecution of complaints by female victims of sexual crimes.


Inflexibility arises from the fact that in every case, irrespective of the reliability of the victim's evidence, the corroboration rules apply. Where corroboration is required as a matter of law, the defendant cannot be convicted if there is none. Where a warning is required, a standardised warning must be given that it is dangerous to convict in the absence of corroboration. The jury may be simply confused by the fact that such a warning has been given in a case where the evidence is strong and would not require corroboration but for the corroboration rules.


The rules are complex and in each case tried before a jury the judge needs to tell the jury what kinds of evidence constitute corroboration. The judge will review the evidence for the jury, but the jury must itself grapple with the complexities and decide whether such evidence constitutes corroboration. Where the trial is not before a jury, the judge must remind himself of these principles and apply them to the facts before him.

Evidence amounts to corroboration only if it is independent evidence implicating the accused. As a result, many things which show, or might be thought to show, that the complainant is speaking the truth do not corroborate her in law. For example -

* a complaint made by the victim shortly after the alleged offence does not amount to corroboration since it is not independent evidence

* the victim's description of her alleged assailant's facial characteristics does not corroborate her subsequent identification of the alleged offender

* the distressed condition of the complainant can amount to corroboration only in exceptional circumstances, since it does not usually implicate the defendant. An exception would be where (for example) a bystander testifies that the accused approached a child and that, shortly afterwards, he saw the child in a distressed condition

* the existence of physical injures can amount to corroboration of the complainant's evidence implicating the defendant in some cases but not in others.

The nature of the defence case may also affect the way in which the corroboration principles apply. For example, if the defendant to a rape charge denies having had intercourse with the complainant, medical evidence of traces of the defendant's semen may corroborate the allegation. (But if a distressed victim douched herself after the incident, such medical evidence may be unavailable.) If the defendant admits that intercourse took place but alleges that it was consensual, evidence of his semen traces would not corroborate the allegation of lack of consent, but serious bruising, or torn or blood-stained clothing may do so. (A victim who remained passive through fear and did not suffer injuries may not be able to produce any corroborative evidence.)

The position becomes particularly complicated where there are two or more defendants who adopt different defences. For example, in a trial of two defendants charged with rape, the first may admit that intercourse took place but allege that it was with consent, and the second may deny that intercourse took place. In such a case, the complainant's distressed condition may corroborate the allegation that the intercourse with the first defendant was without consent, but it does not corroborate the allegation that the second defendant had intercourse with the alleged victim.


Anomalies arise because the corroboration rules are an exception to the general principle that it is the quality, rather than the quantity, of evidence which should count in a criminal trial. As a general rule, a jury is not prevented from convicting on the unsupported testimony of a single credible prosecution witness, even if it is contradicted by several witnesses for the defence. On the other hand, the jury need not believe a witness's testimony, even if it is not contradicted by other evidence and is unshaken in cross-examination.

Where corroboration is required as a matter of law, a lack of corroborative evidence must lead mechanically to an acquittal even where the judge or the jury is satisfied beyond reasonable doubt that the accused is guilty of the alleged crime. This is considered to be a glaring anomaly and contrary to the interests of justice.

A good example of such anomaly and how even judges may misapprehend the meaning of corroborative evidence can be found in the case of R v Cheung Shu Wai [1994] 2 HKC 174. The complainant in the case was around 9 to 10 at the time when she was allegedly sexually abused by her mother's boyfriend who was staying with them at the relevant time. The defendant was charged with and convicted of, amongst other things, rape. The prosecution adduced evidence from a Mr. Yau, who shared a holding cell with the defendant and who was told by the defendant that he had sexual intercourse with the complainant.

The defendant, when convicted, appealed against the conviction on the ground that the judge was wrong to treat the evidence of Mr. Yau as corroboration of the complainant's evidence.

The conviction was ultimately quashed even though the judges of the Court of Appeal were of the view that it was unlikely that the jury would have thought that a ten-year old girl would have consented to intercourse in the circumstances she described. Further, although evidence which simply adds to or supports other evidence can be corroboration, it was nevertheless held that Yau's evidence was only sufficient to prove intercourse but insufficient to corroborate rape.

A further anomaly is that the corroboration rules apply according to technical legal definitions of specified "sexual" offences rather than according to the circumstances of the actual case before the court.

In the case of a sexual offence in which consent is in issue, evidence both of the fact that a complaint was made by the alleged victim shortly after the offence, and of the substance of the complaint, is admissible as showing the consistency of the victim's conduct with her testimony and as being inconsistent with consent. However, a complaint of this kind cannot amount to corroboration because of the technicality that corroborative evidence must be independent of the victim. Therefore, when it is necessary to decide whether the complainant had consented to intercourse, the complaint is treated by one standard but when consent is not raised by the defence and need not be proved or disproved, the same complaint will be treated by another standard. This adds to the burdensome task that the corroboration rules impose on the judge, who has to explain the difference in treatment and the necessity for the difference, and on the jury which has to grapple with the subtleties involved.

Failure to serve the purpose of the corroboration rules

While the corroboration rule is intended to protect the accused, it is not necessarily beneficial for evidence against the accused to be repeated in detail to the jury in the course of the judge's summing up and direction to the jury. Strongly prejudicial evidence would be repeated and thus, however unintentionally, highlighted.


It has been suggested that a warning to the jury is "an essential safeguard for the defendant". In fact, however, trial judges are already under general obligations with regard to doubtful or unreliable evidence, and these obligations will remain even if the corroboration rules are abolished. Defendants would therefore be adequately protected notwithstanding the abolition of the rules.

General obligations of a trial judge in directing the jury

In summing up the evidence in all cases before a jury the trial judge is under a duty not only to remind members of the jury of the evidence but also to use his experience and judgment to assist them to assess and to make sense of it. This is a very clear duty.

Within this duty the judge has a wide discretion in deciding how to sum up. However, he has a particular duty to put the defence case to the jury, a duty that extends even to defences not raised in the accused's own submissions. That duty entails, in respect of doubtful prosecution evidence, the exercise of his judgment to warn the jury of possible reasons why they should not rely on that evidence, or ways in which they should scrutinise or test it before relying on it, and where appropriate, a critical analysis of the prosecution evidence.

This duty of the judge not merely to remind the jury of the evidence but also to make sure that the jury understands the defence case therefore inevitably means that, where items of the prosecution evidence are actually or potentially unreliable or open to criticism, the judge must guide the jury on those matters.

It is also the duty of the judge to give a warning to the jury of the need for caution in assessing the evidence of witnesses who have or may have interests or purposes of their own to serve in giving evidence adverse to the defendant. Depending on the circumstances of the case, the judge may choose to warn the jury of the need to examine the evidence of suspect witnesses with care. In sexual offences cases, as in any others, a complainant apparently acting with a personal grudge or spite, or who has given inconsistent evidence, may fall within this description. The judge should explain that the witness has or may have a personal interest to serve; or he may in his discretion go further, and advise the jury to look for independent evidence that supports that evidence. The overriding rule is that the judge must put the defence fairly and adequately.

This rule is preferable to the corroboration rules since it is specific to the circumstances of each witness, and applies only where there is material to suggest that a particular witness's evidence may be tainted by improper motive rather than because of mechanical categorization of the witness into a particular group.

Control by the Court of Appeal

The Court of Appeal can and will correct the position where the judge has misdirected the jury (or failed to give a direction where one was required) concerning the credibility of a witness. This control applies as much in sexual offences cases as in any other kind of case.


If the corroboration rules are abolished in respect of sexual offences, the general rule that the defence must be put fairly and adequately will remain, as will the general control of the Court of Appeal. Witnesses now within the corroboration rules would be treated, as other witnesses already are, on their merits.

Freed from the mechanical obligation to give a corroboration warning, judges may form the view in some cases that no warning of any kind is required. Judges will nevertheless continue to have an overriding obligation to put the defence fairly and adequately to the jury and to give a warning about the evidence of complainants whom they consider to be unreliable.



The corroboration rules in respect of sexual offences were abolished by the Criminal Justice and Public Order Act 1994. The following guidelines have been adopted by the courts -

* The requirement to give a corroboration warning in respect of an alleged accomplice or a complainant of a sexual offence, simply because a witness falls into one of those categories has been abrogated.

* It is a matter for the judge's discretion what, if any, warning is appropriate in respect of such a witness, as indeed in respect of any other witness in whatever type of case.

* It might be appropriate for the judge in some cases to warn the jury to exercise caution before acting on the unsupported evidence of a witness. There would need to be an evidential basis for suggesting that the evidence of the witness might be unreliable and not because the witness falls into any particular category.

* If any question arises as to whether the judge should give a special warning, it is desirable that the question be resolved by a discussion with counsel in the jury's absence before final speeches

* Where a warning is considered necessary, it should be as part of the review of the evidence and his comments as to how the jury should evaluate it, rather than as a mechanical legal requirement.

* It is for the judge to decide the strength and terms of any warning that the circumstances of the case may require.


The corroboration rules were abolished in 1987 in relation to some specific offences including a range of sexual offences. The abolition has gone even further and provided that the judge should not instruct the jury that it may be unsafe to convict in the absence of corroboration. This approach has been criticized as inflexible because categories are again relied on and the judge's discretion is also fettered, albeit in a different direction.


In the Australian Capital Territory and Victoria, the trial judge is prohibited in most cases from giving a traditional corroboration warning. However, in these jurisdictions the judge may still give a warning upon the basis of the particular facts and circumstances which may affect the reliability of the witness in question.

In New South Wales, South Australia, Tasmania and Western Australia, a corroboration warning regarding the evidence of an alleged victim of a sexual offence is not required by any rule of law or practice. In these jurisdictions, a trial judge may still give such a warning but it is an error for a trial judge to caution a jury in terms which relate the warning to complainants in sexual cases generally as distinct from the complainant in the particular case.

In Queensland, South Australia and Tasmania, there are still mandatory corroboration or warning requirements in the case of complainants of specified sexual offences.

New Zealand

The requirement for a corroboration warning was abolished in 1985 and if a judge decides to comment on the absence of any evidence tending to support any other evidence, no particular form of words is required.

End/Saturday, March 20, 1999