The United States-based pathologist who suggested that American researcher Shane Todd could have been murdered will be testifying via videolink on May 20.

Dr Edward Adelstein, who was engaged by Dr Todd's parents to provide an independent post-mortem report, had initially said he was unable to give his evidence in person, citing personal reasons. This even though the state is prepared to "provide the usual funding that is applicable for foreign witnesses", said the Attorney-General's Chambers (AGC) on Wednesday night.

The same funding will be extended to the computer forensic analyst Ashraf Massoud, who will be testifying in person later in the inquiry, said the AGC, replying to media queries after the third day of the coroner's inquiry into Dr Todd's death. Mr Ashraf was also engaged by the Todds in the US to provide a separate assessment for the inquiry.

The AGC also responded to assertions made by Dr Todd's father, Rick, that DNA evidence had not been properly "looked into".

The state's witness, Mr Kua Guo Wei from the Health Science Authority's (HSA) DNA Profiling Laboratory, had testified on Tuesday that there were up to two unknown persons' DNA on both the strap and the towel found around Dr Todd's neck besides his own.

Mr Kua had told the court that DNA traces left on objects could be weeks, months or years old, and that he was unable to ascertain if the unidentified DNA on each of the items belonged to the same unknown persons nor their gender, He also said that it was impossible to determine through testing if the contributors had all left their DNA at the same time. "Counsels for the next-of-kin did not challenge any other aspects of Mr Kua's evidence," said the AGC.

The 31-year-old American researcher was found hanged in his Chinatown apartment last June. His parents, however, do not believe he had killed himself.

The inquiry continues on Thursday, with Dr Wee Keng Poh, HSA's senior consultant forensic pathologist who supervised the post-mortem on Dr Todd, taking the witness stand.