A former Chinese communist party official at the centre of a sex tape scandal has been convicted of taking more than 3.1 million yuan ($504,500) in bribes and sentenced to 13 years in prison, in the latest move by the Chinese government to crack down on widespread graft.

Lei Zhengfu, the former party chief of a district in the south-central metropolis of Chongqing, did not say whether he would appeal the verdict by the city's No. 1 Intermediate Court on Friday, according to state media.

The punishment meted out to him also includes confiscation of personal assets of 300,000 yuan ($48,800).

Lei's case has riveted the public since video clips went viral of the 55-year-old having sex with a woman hired by property developers, allegedly in an elaborate extortion scheme.

Beijing Institute of Technology law professor Xu Xin said the sentence was more severe than those in earlier corruption cases involving similar amounts of bribes.

"Maybe because of the case's social impact, the court has chosen to be on the harsh end with its sentence," he said.

Lei asked another property developer who had benefited from his patronage to pay hush money of 3 million yuan to the blackmailers. Lei argued that the money was a loan, but prosecutors said the money - which was not fully repaid - amounted to a bribe.

Prosecutors also said Lei took two other bribes - one of $10,000 and another of 100,000 yuan ($16,300) - in return for favours granted through his government position.

Verdicts were expected to be announced later on Friday in a separate case against the woman and the men behind the alleged extortion scheme.