主题：南华早报消息：中央已经同意对周永康展开腐败调查 -- 林子白

(Reuters) - China's former domestic security chief Zhou Yongkang, one of the country's most powerful politicians of the last decade, is helping authorities in a corruption probe and, contrary to media reports, is not currently the target of the investigation, sources told Reuters.

The investigation could take weeks, maybe months, to complete. Even if Zhou is implicated, he is unlikely to follow in the footsteps of disgraced ally Bo Xilai and face prosecution, said the sources, who have ties to the leadership or direct knowledge of the matter.

The scandal involving Bo, who is awaiting the verdict of a trial that concluded last week on charges of corruption and abuse of power, and the rumors surrounding Zhou are the most serious convulsions within the ruling Communist Party in decades. The probe Zhou is helping in has already reached deep into China's state-owned oil companies and several senior executives are being investigated for graft.

President Xi Jinping, who formally took power in March, has vowed strong action against corruption, but he may not yet be powerful enough to take on Zhou, who still wields political clout through protégés he had promoted into key positions.

Any action against Zhou may only be considered after the party's elite 200-member Central Committee meets at a plenum in November, the sources said. Xi will need unstinted support at the meeting, where he is likely to present wide-ranging reforms to rebalance the economy.

"Zhou has not been 'shuang gui'," one source told Reuters, referring to a form of internal investigation in which a suspect is required to confess within a prescribed time and place.

"He was merely asked to assist with the corruption investigation," the source said. All three sources declined to elaborate when asked if the probe involved Zhou's family members or allies at state oil giant China National Petroleum Corp, of which he was president in the 1990s.

"Unlike Bo, Zhou is unlikely to be arrested or put on trial" even if he is implicated in the probe, the source added.