China corruption: Sichuan deputy chief under investigation
China's top prosecution body says it is formally investigating a top provincial chief linked to former security tsar Zhou Yongkang.
The Supreme People's Procuratorate said that Li Chuncheng was being investigated for bribe-taking.
The announcement comes a day after the ruling Communist Party expelled Mr Li, 56.
His fall from grace began in 2012, when he was first put under investigation for alleged discipline violations.
China's disciplinary watchdog said on Tuesday that Mr Li had taken advantage of his position to seek gains for others by accepting bribes in large amounts.
Mr Li first became mayor of Sichuan's Chengdu city in 2001 when Zhou Yongkang was party chief in the province.
Mr Li then went on to become deputy party chief of Sichuan in 2011.
There is widespread speculation that Mr Zhou - China's former internal security chief - is being investigated, although nothing has been formally confirmed by the authorities.
But in recent months several officials linked to Mr Zhou, either via Sichuan or in the oil industry where Mr Zhou built his powerbase, have come under investigation.
Mr Zhou is a former member of the Politburo Standing Committee, China's most powerful political body.
He was also the patron of disgraced politician Bo Xilai, who was given a life sentence for bribery and abuse of power last year.
An investigation into an official of Mr Zhou's seniority would be of enormous political significance.