Zhou Yongkang, the former head of China's domestic security apparatus, has been formally arrested and expelled from the ruling Communist Party, state-run media announced today.
Zhou, 72, is the first member of the elite Politburo Standing Committee to face criminal investigation for corruption.
The arrest of Zhou, who developed a reputation as one of Beijing's most ruthless politicians, is one of the biggest milestones of the sweeping two-year anti-corruption drive under President Xi Jinping.
Zhou, 72, stands accused of accepting bribes, exploiting his power to enrich family members and leaking state secrets, as well as trading money and power "for sexual advantages".
The bringing down of Zhou, the highest ranking Chinese leader ever to face criminal investigation for corruption, and once seen as untouchable due to his control of seniority and networks of vested interests, was cheered by official state media as proof that Xi was serious about cleaning up an officialdom saddled with an institutionalised culture of graft.
"Corruption is a cancer that has invaded the party's healthy tissue," the People's Daily, the party's flagship newspaper, said. "We must use investigating and dealing with Zhou Yongkang's grave violations to advance the struggle against corruption."
President Xi has sought to use his crackdown on corruption as a means to re-establish people's trust in the party, while pushing aggressively to consolidate and centralise his own personal power – in part to push through difficult but increasingly urgent economic reforms as China comes off decades of breakneck growth.
The apparent speed at which Xi has done so prompted US President Barack Obama this week to warn of some of the potential "dangers" that could arise.
"He has consolidated power faster and more comprehensively than probably anybody since Deng Xiaoping," Obama said. "There are dangers in that - on issues of human rights, on issues of clamping down on dissent. He taps into a nationalism that worries his neighbours."
Zhou had been under a cloud since he formally retired from China's elite Politburo Standing Committee in 2012, and an internal party investigation into his affairs was announced in July. The transfer of the case to prosecutors – once part of his political fiefdom – all but ensures Zhou will face trial, conviction and a lengthy sentence.
The announcement carried by China's official Xinhua news agency said investigators found Zhou had leaked party and state secrets, "used his position to give illegal benefits to many people, and took bribes directly and via his family members", as well as abused his position "to help his family members, mistresses and friends gain huge profits through business activities at the cost of state assets".
As well as controlling the police and paramilitary, Zhou had a longstanding influence in China's state-owned petroleum sector, and previous investigations into his family have revealed assets of more than 1 billion yuan ($195 million). His son, Zhou Bin, has also been detained as part of the investigation.
"What Zhou did completely deviated from the Party's nature and mission, and seriously violated party discipline," an official statement from the Supreme People's Procuratorate, the highest agency at the national level responsible for both prosecution and investigation in the country, said. "His behaviours badly undermined the reputation of the party, significantly damaged the cause of the party and the people, and have yielded serious consequences."