HONG KONG, CHINA - TEARFUL 'Milkshake Murderer' Nancy Kissel appeared frail and emotional on Monday as she returned to court for an appeal over one of Hong Kong's most sensational crime cases.

Kissel, dressed in a black top and grey trousers, had to be helped to her seat in the dock by a guard and briefly burst into tears before the hearing began.

The 44-year-old American was sentenced to life three years ago for murdering her high-flying investment banker husband, Robert, by lacing his strawberry milkshake with sedatives and bludgeoning him to death with a lead ornament.

The appeal, which is being held in the southern Chinese territory's High Court, is scheduled to last eight days in front of a panel of three judges.

Several members of Kissel's family, including her father and mother, were in court to hear the opening remarks by her barrister, Gerard McCoy. Kissel took extensive notes during the proceedings.

Mr McCoy told the court that the initial 2005 case, which at three months was one of the longest in Hong Kong's history, was 'a demanding and complicated trial'. He said Kissel would be appealing on the basis that the original trial judge's summing up was too narrow when he defined under what circumstances self-defence could be allowed.

'(The judge) dealt with self-defence in two places (in his summing up). They are not just different, that would not help me, they are incompatible,' Mr McCoy told the court.

Mr McCoy also said he would be introducing new evidence.

Prosecutors in the 2005 trial claimed Kissel stood to gain up to 18 million US dollars (S$24.4 million) in insurance payouts from the investment banker's death.

Driven by a passionate fling with an electrician in the United States, Kissel had manufactured a state of conflict within her marriage that she used as an excuse for killing her husband, said then-prosecuting barrister Peter Chapman.

Kissel's defence team painted her as a loving but long-suffering wife who had been subjected to regular violent attacks by a husband who abused cocaine and alcohol.

But Kissel finally conceded she had killed her husband after he attacked her with a baseball bat after telling her he wanted a divorce and to take away their three young children.

Kissel disposed of the body by rolling it up in an old carpet, before hiding it in storage space at their luxury apartment. She continued to sleep in the same room as the body for several nights, according to court testimony at the original trial.

Some of the bloodstained bedding was visible in the court in evidence bags during Monday's proceedings.

The Kissel family suffered a further tragedy in 2006, when Robert's brother Andrew was found murdered in his house in Connecticut, bound with multiple stab wounds. -- AFP