BEIJING – Authorities are investigating an official in southern China after his purported diaries appeared on the Internet, describing acts of alleged bribery and sexual misconduct, state media said Wednesday.

Han Feng resigned from the Guangxi tobacco monopoly bureau after the publication of his diaries led to accusations of corruption, a lavish lifestyle and improper relations with female employees, the China Daily reported.

"The diaries are not groundless rumours," said Liao Hongxiu, the head of the bureau.

The office was now investigating whether Han violated laws and Communist Party rules, the official Xinhua news agency reported.

China's ruling party has railed against corruption for years, seeking to counter public anger over regular reports of graft, excess and debauchery among officials, and saying such behaviour threatens the party's legitimacy.

The alleged diaries were first posted on Saturday on a popular Internet forum by a man who claimed Han had an affair with his wife, the China Daily said.

The man said he was posting the entries as revenge, but did not say how he obtained the documents.

Over a year-long period up to January 2008, the entries describe regular feasts and excessive drinking five days a week, usually with police, local government officials and tobacco company directors.

Han says he received payments ranging from 2,000 yuan (300 dollars) to 100,000 yuan, and offers details of sexual relationships with five female colleagues.

The case marks the latest instance of an official being forced to step down after allegations of excess appeared on the Internet.

A housing official in the eastern city of Nanjing was jailed for 11 years after Internet users posted photos of him driving a Cadillac, smoking luxury cigarettes and wearing a 14,000-dollar watch.

A local chief prosecutor in the northern Inner Mongolia region resigned after web users accused her of driving a 115,000-dollar sport utility vehicle.