China's former security chief Zhou Yongkang is under probe. Photo: AP
China's Communist Party said on Tuesday it had launched a corruption investigation into former domestic security chief Zhou Yongkang, one of the country's most influential politicians of the last decade.
Zhou, 71, is by far the highest-profile figure caught up in President Xi Jinping's crackdown on corruption. Indeed, Zhou is the most senior Chinese official to be ensnared in a graft scandal since the party swept to power in 1949.
He was a member of the Politburo Standing Committee - China's apex of power - and held the post of security tsar until he retired in 2012.
The party's anti-graft watchdog, the Central Commission for Discipline Inspection, said on its website Tuesday that it is investigating Zhou, 71, for serious violations of party discipline. Although it gave no details, such an announcement typically paves the way for the official to be ousted from the party and face prosecution.
A commentary by official Chinese news agency Xinhua on Wednesday said the investigation "clearly terminated a myth among many people that senior leaders are regarded to be immune from the party discipline regulation and the country's law enforcement."
The announcement ended months of speculation over Zhou amid reports of his family amassing great wealth and as authorities began investigating dozens of his associates including several high-ranking officials and businesspeople. One after another, the associates disappeared into the custody of party investigators, foreshadowing problems for Zhou.
Zhou's son Zhou Bin had also been arrested and accused of "illegal business operations," the Chinese magazine Caixin reported on its website after news of the investigation into his father had been made public.
Zhou was once perceived as untouchable, with expansive patronage networks covering the sprawling southwestern province of Sichuan where he was once party boss and controlled the state oil sector, police and courts.
The announcement of the investigation shows that Xi's anti-corruption crackdown is gathering steam.
Last month, the party said it would court-martial one of its most senior former military officers, Xu Caihou, also on charges of corruption.
The party has already gone after several of Zhou's proteges, including Jiang Jiemin, who was the top regulator of state-owned enterprises for just five months until last September when state media said he was under investigation for graft.
Jiang was previously chairman of state-owned China National Petroleum Corp (CNPC) - Zhou's power base - as well as one of its subsidiaries, oil-and-gas behemoth PetroChina. Zhou served as CNPC's general manager from 1996-1998, having risen through the ranks.