Hu Deping, the eldest son of the late Communist Party general secretary Hu Yaobang and a leading liberal, has publicly denied having any connection to an alleged gangster.
Hu's wife is a fellow director of a charity sponsored by the Sichuan businessman Liu Han, who is accused of being an organised crime boss.
Liu donated 100 million yuan (HK$127 million) in 2007 to the Tiannuo Charity Foundation, of which Hu's wife, Wang Yuying , is director-general.
Liu last week was charged with 15 serious offences - including murder, gun running and bribery - in a case that appears connected to the wider corruption probe into associates of the retired security tsar Zhou Yongkang.
In a statement posted on Sina Weibo and the Hu Yaobang Historical Data website, Hu said he could not remember meeting Liu before.
"One thing is certain, I have never conducted any illegal businesses with Liu and or lobbied for his personal interests," Hu said. "Other people would have definitely known and spoken out if I did anything wrong on his behalf."
The Tiannuo Charity Foundation, according to its website, provides assistance, such as clinics and schools, to economically disadvantaged areas - notably Tibet, where Hu said his wife spends long periods of time.
Wang and Liu were both directors of the foundation when it was established in 2007. Three other directors were a pair of businessmen and a former senior official in Sichuan.
Liu was widely known for his charity work before his fall, having donated hundreds of millions of yuan to various charities and funded some 20 primary schools in poor regions of Sichuan. He was ranked as the province's leading philanthropist in 2008 and 2009. Hu publicly dismissed allegations in July that he had an undisclosed luxury home in an upmarket Beijing estate.