A Hong Kong newspaper says China has decided to start a corruption investigation into retired politician Zhou Yongkang, who until last year was one of the country's elite leaders.
The South China Morning Post on Friday said the decision to launch the investigation was confirmed by sources "familiar with the leadership thinking" of China's Communist Party.
The 70-year-old Zhou was a member of the elite Politburo Standing Committee, China's highest governing body, from 2007 to 2012. He also oversaw China's sprawling state security apparatus.
China's government has not commented on any investigation. If confirmed, it would be the first time in decades that the party has investigated economic crimes by a former or current Standing Committee member.
Joseph Cheng, a professor of political science at the City University of Hong Kong, said he thinks it is not likely that President Xi Jinping, who just came to power last year, would pursue graft charges against such a prominent, well-connected ex-official.
"The present leadership does not seem to want to be involved in political controversies or to be involved in serious factional infighting," he said. "Xi Jinping appears to be interested in maintaining some kind of balance, avoiding controversies, avoiding confrontations."
Some also pointed out that Zhou's name was mentioned this week in a state media report that said he laid a wreath at the grave of a deceased party official, in what could be a sign he remains politically active.
There had already been rumors about a possible corruption case against Zhou. The former leader is a close ally of disgraced former Politburo member Bo Xilai, who himself is awaiting a verdict in his trial last week for taking bribes, embezzlement and abuse of power.
The Communist Party has acknowledged widespread corruption within its ranks. It has made a highly publicized effort to crack down on graft, pursuing charges against several lower level officials.
But analysts say it is riskier for Beijing to go after senior officials, many of whom have reportedly used their leadership positions to amass huge amounts of wealth.
The New York Times reported last year that the family of former prime minister Wen Jiabao had accumulated $2.7 billion in hidden assets. China denied the story, calling it a "smear" with "ulterior motives."
The South China Morning Post's report said that Zhou, who also served as the ministry of land and resources and the party chief of Sichuan province, will be investigated for his alleged part in oil field and property deals that profited his family.
If an investigation were to be carried out, it is not clear whether Zhou would face criminal charges, such as Bo, or be subject to an internal party disciplinary committee.