Part of a report offered by the defense was read out in court Tuesday. It criticized the government's analysis as being insufficient in documenting the precise amount and effect the drugs may have had on the victim.

The government's drug analysis expert, Cheng Kok-choi - who earlier said the combination of drugs he found in Kissel's stomach was the most unusual he had seen in his 10 years of forensic experience - said he could not comment on the quantity of drugs or whether they would produce a ``significant pharmacological effect.''

The prosecution contends that Robert Kissel's wife, Nancy, drugged her husband with a spiked milkshake and then beat him to death as he lay unconscious. On trial for his November 2003 murder, she denies the charge and is out on bail. She told police that her husband was drunk and had assaulted her when she refused him sex before he disappeared. His body was discovered in a store room in the couple's luxury apartment building.

The defense report, written by Olaf Drummer, an associate professor of forensic medicine at Australia's Monash University, also stated that an analysis of a hair sample from the deceased suggested that he had taken one of the sedatives found in the body, Stilnox, a sleeping pill, two to three months prior to his alleged murder.

Cheng agreed that ``hair analysis is a well-established method'' in drug detection and, based on Drummer's analysis, it seemed ``he [the deceased] was using it [Stilnox] habitually.''

Cheng also agreed with Drummer that it is possible for traces of different drugs to be present in a corpse due to the chemical process of decomposition and that those traces may not have originated through oral administration.

Drummer is well-known in the field of toxicology, and he has published widely and lectured frequently in universities and government laboratory workshops, defense counsel Alexander King said. Cheng agreed and said he had also attended Drummer's lectures.

Cheng reiterated that, although he found ``insignificantly low'' levels of alcohol from the samples, he could not rule out that they were the last trace from an earlier drink. Furthermore, urine and liquid from the eyeball ``is the best sample for testing alcohol,'' but he did not receive such samples.

Cheng said that the screening test would not have picked up evidence of cocaine which, in any case, becomes immediately dissolved, or hydrolyzed, in the stomach.

``Did you actually carry out a test to see if the hydrolyzed products were present in the sample?'' asked King. ``No,'' Cheng replied.

Pharmacology professor Yeung Hok-keung Tuesday explained the composition, effect and normal usage of the individual drugs found in the stomach of the deceased.

Yeung had been present in court to hear the testimony last month of a Kissel neighbor, Andrew Tanzer, who said he was given the same milkshake as Kissel on the afternoon of the alleged murder.

Tanzer's wife said her husband had turned red, drifted in and out of consciousness, talked incoherently and devoured three tubs of ice cream ``like a baby'' after he was served the pink milkshake on November 2, 2003.

Yeung said the five drugs found in the stomach - Anatryptaline, Rohypnol, Lorivan, Stilnox and Axotal - are generally used in low dosage to treat depression, anxiety or insomnia.

The drugs can cause dizziness, drowsiness and amnesia, and induce a coma in the case of an overdose. If taken with alcohol, the sedative effect would be enhanced, added Yeung.

The prosecution alleges the accused was prescribed Stilnox, Rohypnol, Anatryptalene and Lorivan on several occasions before the murder. Yeung said he found it difficult to understand why two sedatives and a sedating anti-depressant were prescribed October 30, as explained by the prosecution. ``One on its own'' would be sufficient, he said.

The case continues before Justice Michael Lunn.

albert.wong@singtaonewscorp.com