LANGFANG, China (AFP) - A former top Chinese economic planning official was convicted of bribery on Wednesday and sentenced to life in prison, the court said, after a former lover went public with a litany of accusations against him.

The guilty verdict against Liu Tienan, once deputy director of the National Development and Reform Commission, China's top economic planning agency, is the latest step of the Communist Party's much-publicised anti-corruption campaign.

"He is convicted of bribery and is sentenced to life in prison," the Langfang Intermediate People's Court said on a verified account on Weibo, a Chinese version of Twitter.

He was convicted of taking 35.58 million yuan (S$7.6 million) in bribes, the court said.

"The court holds that the defendant Liu Tienan as a government employee took advantage of his post to seek gains for others, illegally took cash or gifts from others by himself or via his son Liu Decheng. His activities amounted to committing the crime of bribery." The case was "based on clear facts and concrete and sufficient evidence", it added.

Beijing authorities picked the court in Langfang, a desolate and bleak industrial city in Hebei province, an hour's drive south of the capital, to hear the case.

A large police presence patrolled outside the court, where the road was blocked off and a parade of police vehicles drove up and down the street, while a group of protesters complained about local government wrongdoing.

Liu fell after his mistress gave incriminating information to a prominent journalist who then posted online her accusations of shady business deals, fake academic credentials and death threats.

Communist Party authorities have waged a much-publicised anti-graft campaign since Xi Jinping ascended to the organisation's leadership two years ago.

But critics say no systemic reforms have been introduced to increase transparency to help battle endemic corruption.

Liu had ties to former security czar Zhou Yongkang and former head of China National Petroleum Corporation Jiang Jiemin, both now under investigation for corruption.

"There's a political motivation behind this case," said Willy Lam, a politics specialist at the Chinese University of Hong Kong.

"If he had belonged to the right faction within the party, he would have been protected even with his dirty laundry being aired on the Internet."