The report gives the first inkling of why the once high-flying CEFC chairman, Ye Jianming, has disappeared from public view after it was revealed in March he was under investigation for suspected economic crimes.

The businessman ranked second in Fortune magazine's "40 Under 40" list of the world's most influential young people in 2016, but the conglomerate he created is now being dismantled under a mountain of debt.

Until now, authorities had given no information about any of the allegations against Ye.

But on Thursday at the corruption trial of former official Wang Sanyun in Henan, prosecutors alleged that Wang had accepted bribes from Ye in 2011, CCTV reported.

Wang was Communist Party chief of northwestern Gansu province from 2011 to 2017.

The bribes helped CEFC acquire a stake in Hainan Bank, and the favour was channelled through Hu Huaibang, then chairman of Bank of Communications and later chairman of major CEFC creditor CDB, the report said.

Wang is accused of taking bribes from multiple sources worth about 67 million yuan ($9.7 million) from 1993 to 2017, according to the indictment.

The former provincial chief was also accused of helping CEFC subsidiary CEFC Hainan to obtain $4.8 billion in financing from CDB when Hu served as the policy bank's chairman. Hu stepped down as CDB chairman in September.

Wang pleaded guilty to the charges after evidence was presented, according to CCTV.

CEFC grew in a few years from a niche fuel trader into a diversified conglomerate with assets across the globe and more than 30,000 employees. In September last year it agreed to buy a $9.1 billion stake in the Russian oil major Rosneft.

But in recent months CEFC's creditors, led by CDB, have been conducting sales of the debt-laden conglomerate's global assets, including oil and gas stakes in Abu Dhabi and Chad, and properties in Europe and Shanghai.

The Zhengzhou Intermediate People's Court said its verdict on the Wang case would be delivered at a later date.

CDB and Bank of Communications did not immediately respond to requests seeking comment. Ye and Hu could not be reached for comment.

CEFC did not respond an email request for comment.

(Reporting by Shu Zhang and Aizhu Chen; Editing by Stephen Coates)

By Shu Zhang and Chen Aizhu