Hong Kong – Dubbed the “milkshake murderer” for one of Hong Kong’s most notorious crimes, American Nancy Kissel has lodged a fresh bid to reduce her life sentence for murdering her banker husband in 2003.

The 51-year-old lost an appeal in 2014 against her conviction for drugging her husband – a senior executive at US bank Merrill Lynch – with a sedative-laced strawberry drink before clubbing him to death with a lead ornament in their luxury home in the southern Chinese city.

Her case gripped the former British colony, shining a spotlight on the elite expatriate community, and featuring sensational allegations of a heady mix of adultery, violence, spying, greed and enormous wealth.

Kissel is currently serving out her life sentence at Hong Kong’s high-security Tai Lam Centre for Women.

Her lawyers filed a writ to the city’s high court on Wednesday saying a government department that periodically reviews sentences of long-time inmates “wrongly” refused to shorten her sentence when it looked at her case in April.

“Given…the applicant’s demonstration of remorse and repentance, the respondent acted unreasonably,” the writ says, referring to the city’s Long Term Prison Sentences Review Board.

The writ argued it was “highly unlikely” that Kissel would commit another offence and that she wished to be transferred to the US – a prospect more likely if her sentence was reduced.

“The applicant is a foreign prisoner who is likely to be deported upon completion of any converted determinate sentence so that she and her family…have some idea as to what the future holds,” the writ said.

The review board makes suggestions to Hong Kong’s chief executive about inmates it deems suitable to be released before the end of an imposed sentence.

The Michigan-born mother-of-three was first convicted of murder and handed a life sentence in 2005. The city’s top court overturned the conviction in February 2010, citing legal errors, and ordered a fresh hearing. But she was convicted again in 2011 and then lost the final appeal in 2014.

At her 2011 retrial, Kissel sobbed as she told the jury she had endured physical and sexual abuse at the hands of her husband.

She maintained she acted in self-defence and offered to plead guilty to the lesser charge of manslaughter.

Prosecutors accused Kissel of rolling up her husband’s body in a carpet and covering his head with plastic after killing him in their luxury home at the hillside Parkview apartment complex.

She left the body in the bedroom for days before hiring workmen to carry it to a storeroom, they said.

Prosecutors also argued that Kissel stood to gain up to US$18 million (S$24.31 million) from the death of her wealthy husband, saying she planned to run away with a television repairman with whom she admitted having an affair in the US.