A recent Hong Kong case sheds light on the difficult question of how to handle evidence from dementia sufferers. In Chan Sung Lai v Chan Sung Lim Paul and Chan Chun Chung [1958 /2011] a dementia sufferer had given a statement after being diagnosed, but before being declared mentally incapacitated.

As the dementia sufferer had been declared mentally incapacitated (and therefore unable to swear his evidence) before the trial date, the statement could only be admitted as hearsay. The Court considered the factors which would influence whether or not it should be admitted.


Chan Sung Lai (Peter) and his father (Chan Chun Chung, the father) invested in two flats (the properties). One was held as joint tenants and the other as tenants in common. The arrangement was that Peter managed the properties and collected the rent, some portion of which was put towards the overseas education of Peter’s daughter. Prior to April 2011, there was no suggestion that the father was unhappy with Peter’s management of the properties or application of the rental income.

In April 2011, Chan Sung Li (Paul), who was Peter’s younger brother, told Peter that he had discovered the ownership of the properties. Shortly thereafter the father asked Peter to account for rent received and various disagreements arose about the management of the properties. These disagreements culminated in the father’s execution of a notice of severance in respect of the property held as joint tenants. Paul also alleged that the father had paid the full purchase price for one of the properties. Peter sought various orders to confirm his beneficial ownership of the properties and to avoid the notice of severance.

State of the father’s health

In early 2011 concerns arose about the father’s health. In particular, his memory worsened. In April 2011, he was diagnosed with mild progressive expressive dysphasia. This is an illness which impairs the patient’s ability to produce language. In September 2011 he was diagnosed with mild dementia. Medical reports from October that year showed that his memory was significantly impacted.

In November 2014 a psychiatrist stated that the father was a “mentally disordered” person within the meaning of the Mental Health Ordinance. Neither Peter nor his lawyers were informed of this for several months.

The witness statement

The father made a witness statement on 7 August 2013. This date was after the diagnosis of dementia, but before the date upon which the father was officially declared “mentally disordered”. It is settled law that unless a witness makes a statement public by verifying it on oath in the witness box it does not become evidence in the trial. The father was unable to do this, having been declared a “mentally disordered person”. A hearsay notice was therefore served by the father’s solicitors seeking to have the father’s evidence admitted. A key part of the case became the decision by the Court as to whether the witness statement was admissible evidence.

Hearsay evidence is admissible unless:

  • A party against whom the evidence is to be used objects to its admission; and
  • The Court is satisfied, having regard to the circumstances of the case, that the exclusion of the evidence is not prejudicial to the interests of justice.

Peter objected to the evidence. He argued that a witness statement made by a person who at the time of making the statement was suffering from dementia was a statement to which no weight at all can be attributed. The statement could not be tested by cross examination.

Consideration of the admissibility of the statement

The Court noted that the best evidence as to the circumstances of the drafting of the statement would have come from either the psychiatrist who examined the father on 28 August 2013 (ie three weeks after the making of the statement) or the solicitor who took the statement. Neither was called as a witness. The Court held that the appropriate inference to be drawn from the absence of the psychiatrist and the solicitor was that neither would have been able to support the contention that the father was mentally capable of making a statement.

The relevant considerations for placing weight on a witness statement are included in section 49 (2) of the Evidence Ordinance. The Court found (amongst other things) that the statement was not contemporaneous with the events described, but would have required the father to remember events that occurred over six years previously. Given the significant deterioration of the father’s memory, this was problematic. This factor counted against the admission of the statement.

Moreover, Paul was the “driving force” behind the litigation. Given the father’s mental state, a very strong inference was drawn that he must have had help preparing the statement. The Court was “satisfied that it is more likely than not that the witness statement was prepared by the solicitor, with assistance from Paul…This factor counts strongly against the admission of the statement.” Paul also had an interest in misrepresenting matters, because he would benefit from any gain to the father’s estate arising from the action.

The judge said that he had given the matter “anxious consideration“, as he was aware that if he excluded the statement, there would be no evidence to counter that of Peter in relation to the circumstances of the purchase of the properties. However, he found that the statement must have been made with a great deal of assistance. Having regard to the limited ability of the father to remember matters and express himself clearly, it was appropriate to see the statement as being a statement of Paul and the solicitor, rather than of the father. No weight could be placed upon it. It was excluded as hearsay.

Conclusions – factors that will be relevant in ascertaining the admissibility of a statement made by a dementia sufferer

  • An inference can be drawn from a witness not having been called if they could have shed light on the mental state of the dementia sufferer at the time of making the statement;
  • If another person can be inferred to have been involved in the making of the statement this will go against admission of the statement, in particular if that person is interested in the outcome of the litigation;
  • If the statement would have required significant exercise of long term memory and the dementia sufferer can be shown to have been suffering from memory loss at the time of the making of the statement, its reliability can be called into question; and
  • Similarly, a statement made by an individual who has difficulty expressing him or herself will be of questionable value.

It is likely that difficult decisions such as the one in Chan Sung Lai v Chan Sung Lim Paul and Chan Chun Chung [1958/2011] will arise more and more frequently, given the aging population in Hong Kong and concurrent rise in the rates of dementia. It may appear that taking a statement early is a proactive way of handling the problem, but if by trial date the sufferer is unable to swear the evidence, it can only be admitted as hearsay. The Court will then have to consider a combination of the factors listed above in deciding whether or not to admit the evidence. In addition, even if it is admitted, the weight placed on it may be minimal, given that it will not be possible to cross examine the witness.