The English-language South China Morning Post, quoting sources ''familiar with the leadership's thinking," said China's current and retired top leaders reached the decision in early August in a secretive meeting at a seaside resort town to investigate Zhou Yongkang, who oversaw China's judicial system and served on the Politburo Standing Committee, the apex of political power.
It has been several decades since a Politburo Standing Committee member has been investigated for economic crimes, whether incumbent or retired. The reported investigation into Zhou, who retired from the panel last November, may illustrate the new leadership's determination to exempt nobody in its fight against endemic corruption.
While sources told SCMP the investigation against Zhou is not politically motivated, Zhou has been considered a close ally of disgraced politician Bo Xilai. Bo stood trial this past week on charges of taking bribes, embezzlement and abuse of power and is awaiting a verdict. Before Bo's fall, it was widely believed that Zhou was grooming Bo as his successor and supporting Bo's bid for a seat on the Standing Committee.
Zhou also has drawn widespread criticism for his association with a national policy to maintain social stability at all costs, using the state power to suppress voices of social critics and political dissidents. Rights lawyers and political observers have said the policy has exacerbated social conflicts in China.
The SCMP report said the investigation, rumored for months, will focus on oilfield and property deals that have benefited Zhou and his family. The Hong Kong paper's report could not be independently verified. Requests for comment were faxed to the State Council Information Office, the Cabinet's press office, and the Communist Party's propaganda department while calls to the Ministry of Supervision rang unanswered.
Zhou, 70, graduated from Beijing Petroleum Institute and had a long-running career in the petroleum industry, where he rose through the ranks to become the general manager of the China National Petroleum Corp., the country's biggest oil and gas company.
On Monday, authorities announced the party would investigate Wang Yongchun, CNPC's deputy general manager, on suspicion of "severely violating disciplines." Wang is said to be a close associate of Zhou.
The investigations have since been broadened to three more CNPC executives.
Also, political associates of Zhou in the southwestern province of Sichuan, where Zhou served as a party chief between 2000 and 2002—have come under investigation, including Li Chuncheng, former provincial deputy party chief, and Guo Yongxiang, former vice governor.
"One by one, they fell, which clearly showed they were approaching him. The possibility is fairly high that they have come to a resolution" to investigate him, said Chen Ziming, an independent political commentator.
In China's politics, authorities have typically used prosecution on economic charges to ostracize politicians who have lost out in factional fights, while they try to avoid airing dirty political laundry that threatens the legitimacy of their rule.
Meanwhile, Beijing is stepping up its anti-corruption campaign, and President Ji Xinping has told the public that it would target "tigers" and "flies" alike.
SCMP said it is unknown if the investigation of Zhou will remain internal or become public, adding to uncertainty over whether Zhou would be disgraced openly.
For now, there has been no mention of the investigation in China's state media, but he was last mentioned in state media when he sent a wreath to the funeral of a party veteran, a sign that he was still politically active.