THE Chinese widow of a British businessman thought to have been murdered in a case that has rocked China's political establishment has been gagged by local police.

Neil Heywood, 41, was found dead in his hotel room in China's south-western city of Chongqing last November. The family initially did not suspect foul play. However, in a stunning twist, state media announced Gu Kailai, wife of Chongqing's disgraced Communist Party boss Bo Xilai, and a household assistant were "highly suspected" of killing Mr Heywood and have been detained.

Mr Heywood's widow, Wang Lulu, who lives with her two children on the outskirts of Beijing, has not commented publicly about the case.

"Police officers questioned her recently and warned her not to speak to foreign media," a source with direct knowledge of the casesaid, requesting anonymity.

He declined to speculate why police gagged her. Chinese authorities customarily warn families of jailed dissidents and crime suspects not to talk to the media.

State media cited a dispute over unspecified "economic interests" between Mrs Bo and Mr Heywood.

Asked what Mrs Heywood's views were after the revelation implicating Mrs Bo in the scandal, another source close to the family said: "It's still difficult to believe. It was absolutely not necessary. The two families were very close. She [Mrs Bo] was the godmother of [Mr Heywood's] children."

Mr Heywood's 11-year-old daughter and seven-year-old son attend an international school in Beijing.

The scandal is the most divisive the party has faced since Zhao Ziyang was sacked as party chief in 1989 for opposing the army crackdown on student-led demonstrations centred on Tiananmen Square in Beijing.

Before his fall from grace, Mr Bo, 62, was widely seen as a contender for a post in China's top leadership committee. He was suspended this week from the Party Politburo and Central Committee and is being questioned by anti-corruption investigators. His wife has yet to be indicted. They have disappeared from public view. Their son, Bo Guagua, is studying at Harvard University.

The scandal came to light after Mr Bo's estranged vice-mayor, Wang Lijun, sought asylum at the US Consulate in nearby Chengdu in February, after confronting Mr Bo with his suspicions about Mr Heywood's death.

Mr Bo's sympathisers were convinced he was the victim of a power struggle. Before his downfall, Mr Bo said during the annual full session of parliament in March that unspecified people were "pouring filth" on him and his family.

In March, Mr Heywood's bereaved relatives in Beijing and London said they did not suspect foul play at the time and denied Mr Heywood was cremated against their wishes.

Chongqing police had initially attributed death to cardiac arrest due to over-consumption of alcohol, but the British Embassy in Beijing asked China to reopen investigations into the case. Mr Heywood's family said then he was not a heavy drinker, but a chain smoker and that his father, Peter, also died of a heart attack after drinks over dinner at his London home in 2004 at age 63.

The British Embassy had requested a meeting with the widow yesterday but had no immediate comment.