A Chinese journalist was jailed in 2010 after criticising a prominent anti-gang campaign launched by Bo Xilai, the politician at the heart of a major scandal, a rights group said Friday.

Bo, a rising star once tipped to join the top echelons of power in a key leadership transition later this year, was ousted as Communist Party leader of the megalopolis of Chongqing on March 15.

On Friday, the Chinese Human Rights Defenders (CHRD) group revealed that Gao Yingpu -- a journalist in the sprawling city in southwest China -- was jailed for three years in 2010 for "endangering state security" after a secret trial.

Quoting his wife, CHRD said Gao had criticised a campaign launched by Bo in Chongqing in 2009 that saw scores of mobsters and corrupt officials jailed or executed in an anti-graft drive that riveted China and drew wide praise.

Gao's wife was not immediately available for comment when contacted by AFP, and it is not know why she chose to speak out now.

In the years that followed the campaign's launch, details have emerged about alleged disregard for the rule of law -- with accusations of widespread use of torture to extract confessions.

At the time, they were mostly swept under the carpet.

But since Bo's sacking, weeks after Wang Lijun -- his former police chief and right-hand man -- fled to a US consulate and reportedly demanded political asylum in a serious embarrassment for the the ruling party, more damaging information has begun to emerge.

A British businessman, who had done work for a strategic-intelligence firm and whose death in Chongqing last November has raised suspicions of foul play, is rumoured to have been linked to Bo and his family.

The British government has called on Chinese authorities to investigate his death.

Wang, meanwhile, has been placed under investigation. The reasons behind his apparent attempted defection are still unclear, although reports suggest he may have been involved in probing one of Bo's family members for corruption.