The screen grab of China Central Television shows Jiang Jiemin in court in October.[Photo/CCTV]

The wife of disgraced former energy chief Jiang Jiemin played a key role in his corruption case, a recent report by the Beijing News disclosed.

Jiang, 61, used to lead China National Petroleum Corporation (CNPC), the nations's biggest petroleum company. Last October, he was sentenced to 16 years in prison for accepting bribes, abusing power, and holding a large amount of property that he could not have afforded from his legitimate earnings.

Between 2004 and 2013, Jiang was the deputy general manager, general manager, and chairman of CNPC, as well as chairman and CEO of PetroChina Co Ltd. He was promoted to become head of the State-owned Assets Supervision and Administration Commission in March 2013.

Jiang used his position to benefit from others with projects and job promotions, then accepted bribes valued at 14 million yuan ($2.3 million). At the request of Zhou Yongkang, the former security chief charged with corruption on April 3, Jiang also helped gain huge benefits from other people by obtaining oil and gas field exploration rights and bidding for gas turbine generating projects, resulting in grave losses to State assets.

According to the report, most of the briberies were paid to Jiang's wife, Shi Kuiying, who is a retiree from a subordinate unit of CNPC. Shi often attended banquets invited by bribers and asked Jiang's subordinates to do things directly. After taking the bribery, Shi would inform Jiang, who then would use his position to gain benefits for the bribers.

An insider quoted by the report said that sometimes when the bribers were refused by Jiang, they would try to bribe Shi Kuiying to persuade her husband.

"Jiang Jiemin looked plain. Sometimes he would take a walk with his wife. It's hard to tell that he was a high-ranking official," Jiang's neighbor in an upscale community in Beijing recalled.

"But his wife was always well dressed, arrogant and seldom talks to neighbors," the neighbor said.

The couple gave great favors to China Huayou (Group) Corporation, a wholly-owned subsidiary of CNPC in securing the group's profitable operations and expanding its operation overseas.

Former general manager of Huayou, Wang Wencang, helped Jiang's family buy properties and decorate the houses. Wang once gave Shi Kuiying a mink coat worth 168,000 yuan.

Insiders say among the 14 million yuan Jiang pocketed, some 12 million is from Wang, who was probed in September 2013.

The report said Shi is indulgent to her son, Jiang Feng, who is fond of refitted cars. Jiang Feng was put under investigation after taking four cars as payment for being a broker in a contract of one of CNPC's subordinate company.

Charges against Jiang's wife and his son are undergoing judicial procedures, according to the report.

Among the items discovered in Jiang's home aside from the 1 million yuan in cash, there are 22 gold products, 23 pieces of jewels and jades, 23 expensive watches, all worth more than 10 million yuan.