Prosecutors presented evidence from a private investigator hired by Robert Kissel to spy on his wife because he suspected her of infidelity.

Nancy Kissel, 40, who has pleaded not guilty and is out on bail, is alleged to have given her banker husband a spiked milkshake that left him unconscious as she bludgeoned him to death with a metal ornament November 2, 2003, before wrapping his body in a carpet and stashing it in a storeroom.

She told police officers at the time that he had hit her while prosecutors say she plotted his murder for personal gain. On Friday Daniel Wu, an orthopedic surgeon and sports injury specialist, testified that although he had prescribed a number of drugs for Robert Kissel to alleviate back pain, he did not supply the drugs allegedly used by the defendant in the milkshake.

Under cross-examination, defending counsel Gary Plowman SC, observed that Wu had also treated the victim for injuries to his right hand.

In September 1999, he diagnosed Kissel with a fracture to the fifth knuckle of his right hand above his little finger.

The injury is ``usually caused by a punching movement or action against whatever object,'' he said.

Treated at Adventist Hospital for the injury, the banker's admittance sheet said he had ``punched the wall.''

The injury caused a deformity that required an operation and a month in a sling.

That operation revealed an old fracture that was again the probable result of a clenched fist striking an object.

Private detective Rocco Gatta, an employee of the Alpha Group that had spied on Nancy Kissel in Vermont in the United States while she and the couple's children were sheltering from the SARS epidemic, provided a running commentary for the court while his surveillance tapes were shown.

During two sessions of surveillance in June and July 2003, he noted that on four occasions a blue van was parked discreetly near the a ``multimillion dollar'' home.

On each occasion, the blue van would park either in a ditch or halfway up the long drive, out of sight from both the main road and the house.

The van would drive off in the middle of the night, without turning on its headlights until it reached the main road.

The registration of the number plates on the blue van revealed the owner to be Michael del Priore, Nancy Kissel's alleged lover.

The testimony of an investigative officer working for New York Life Insurance was also read to the court, confirming that Nancy Kissel was the primary beneficiary of life insurance policies worth US$5 million (HK$39 million).

On cross-examination a member of the defense team noted that Robert Kissel's brother and sister had refused to answer questions from insurance investigators in 2002. Outside sources are usually required to confirm details of the insured and the investigators had to inquire about his sports injuries and driving record.

Another question was ``how often does he drink.'' Andrew Kissel and Jane Clayton, the deceased's sister, refused to provide that information.

Clayton was also recalled to the witness box to answer questions about e-mails she had previously been unable to access. She said she had forwarded a list of marriage counselors to her brother in January 2003 after she noticed her sister-in-law had been ``distant'' during a skiing trip in Whistler, Canada, over Christmas 2002.

Defense counsel Plowman observed that ``there is no mention anywhere in this [e-mail] of marriage guidance counselors as such.''

The e-mail listed qualified psychiatrists and clinical psychologists rather than marriage counselors.

Clayton replied that many marriage counselors have a background in psychiatry.

``Let me put it to you,'' said Plowman, that ``you and Robert either in Whistler or thereafter had discussed the possibility that Nancy Kissel needed some form of help.''

The trial continues Monday and is expected to last for eight weeks before Justice Michael Lunn.

albert.wong@singtaonewscorp.com