China's former security chief Zhou Yongkang jailed for life at secret trial

Former Chinese security chief Zhou Yongkang, the highest ranking ex-official to be investigated for corruption in decades, was sentenced Thursday to life in prison on charges of bribery, abuse of power and leaking state secrets, state media said.

Zhou "admitted guilt" following a secret trial in the northern city of Tianjin, the official Xinhua news agency said.

Zhou is a former member of the ruling Communist party's all-powerful Politburo Standing Committee, and wielded extensive power as head of the police and courts until his retirement in 2012.

China's President Xi Jinping has vowed to bring down high-ranking officials in a campaign against endemic corruption, but critics say that lack of systemic reforms mean the drive is open to political abuse.

After months of rumours, the party announced in July that Zhou was being investigated, before he was expelled and arrested last December.

Xinhua added that the trial was "not open," and its date was not announced in advance.