BEIJING (REUTERS) - The south-western Chinese megalopolis of Chongqing will purge the "vile influence" of its former top official Sun Zhengcai after he was expelled from the Communist Party for corruption, the city government said, praising the move as "brilliant".

Sun, a senior official once considered a contender for top leadership, had been party chief of the city until an abrupt announcement in July that he had been replaced by a rising political star close to President Xi Jinping, Chen Miner.

Sun was put under investigation later in July and on Friday (Sept 29), the party announced he would be prosecuted for corruption, accusing him of leaking secrets, bribery and abusing his power.

In a front page story on Saturday, the official Chongqing Daily said a city party meeting overseen by new party boss Chen offered strong support for the Sun decision, which comes just weeks before the party opens a key twice-a-decade Congress.

"Everyone said they resolutely uphold the party's decision, resolutely practise the party's spirit and will resolutely purge Sun Zhengcai's vile influence," the paper said. "The party's decision to investigate and handle Sun Zhengcai's serious breach of discipline is completely correct, absolutely brilliant, came just at the right time and has completely won the hearts of the party, the military and the people."

It has not been possible to reach Sun directly for comment and unclear if he has been allowed to retain a lawyer.

He is certain to be found guilty when his case comes before a court as the party controls the legal system, which will not challenge its accusations. These include trading power for sex and sloth.

Chongqing, one of China's most important cities, is perhaps best known outside China for its association with its disgraced former party boss Bo Xilai, who was once himself a contender for top leadership before being jailed for life in 2013 in his own dramatic corruption scandal.

The government has yet to give exact details of what Sun is suspected of.

The official newspaper of the north-eastern province of Jilin, where Sun was party chief from 2009 until late 2012, implied on Saturday at least some of his crimes took place there too.

"While in Jilin he neglected Jilin's development, put his undivided attention on promotion, and seriously damaged Jilin's political ecology," the paper said, summarising a provincial party meeting to condemn him.

Sun had been seen as a potential candidate for elevation at next month's party Congress and as a possible future premier.

But sources with ties to the leadership and foreign diplomats say Sun had been out of favour after the party's corruption watchdog in February criticised Chongqing authorities for not doing enough to root out Bo's influence.

Sun is the latest senior official to be investigated under Xi's sweeping crackdown on corruption.

The party's official People's Daily said on Saturday the move against Sun augured further struggles ahead, saying major victories did not mean the anti-corruption fight was over.