BEIJING - A former senior judge awaiting trial in a massive organised crime crackdown in southwest China hung himself in jail using the drawstring of his underwear, state media said Monday.

Wu Xiaoqing, 57, was found hanging from his detention cell doorway in Chongqing city on Saturday afternoon and pronounced dead several hours later after being rushed to hospital, the official Xinhua news agency said.

A former director at Chongqing's high court, Wu had been charged with accepting 3.5 million yuan (512,700 dollars) in bribes and being unable to explain the source of 5.2 million yuan in his possession, the report said.

Wu's case was one of a series in a huge mafia crackdown that has rocked Chongqing and implicated up to 200 city officials, including the former head of the city's judiciary and the deputy chief justice of the high court.

The officials are charged with accepting large sums of money to protect organised crime and illegal gambling rackets.

Up to 1,500 alleged mafia figures have been detained, state press reports have said.

Wu had also been charged with abusing his powers to extort money in the auction of land, the report said.

His mistress and the 10 lawyers he worked with are also under investigation, it added.

He hung himself with the drawstring of his cotton underwear from the door of his cell, which was out of range of a closed circuit camera in the jail, the report said.

His cellmates were napping at the time, it added, while two detention centre guards are being investigated over the suicide.

Wu left a note, but its contents have not been publicised.

Wu's suicide adds another chapter to the Chongqing cases that have gripped the nation with lurid tales of sex and corruption in the municipality, which boasts a population of more than 30 million.

So far six people have been sentenced to death and scores of others jailed for up to life in prison.