BEIJING (Reuters) - China has dismissed a top official in the southwestern province of Sichuan after putting him under investigation for "serious disciplinary violations", the official Xinhua news agency reported on Thursday.

Sichuan's deputy party boss, Li Chuncheng, is the most senior person to be investigated since Xi Jinping became leader of the Chinese Communist Party.

Xi has vowed to crackdown on corruption, warning last month that if corruption was allowed to run wild, the party risked major unrest and the collapse of its rule.

"The central government has decided to remove all leadership positions of (Li)" due to suspicion of "serious disciplinary violations", Xinhua said in a brief report on its website, without elaborating.

The term "serious disciplinary violations" usually results in criminal charges.

Xi, who was named party leader in mid-November and will assume the presidency at an annual meeting of parliament in March, has appointed Wang Qishan, a man known as "the chief firefighter" for his ability to deal with crises, as his top graft fighter.

State media said a week ago that Li was being investigated by the party's discipline watchdog.

Li had served in Sichuan since 1998 and had been party chief of the prosperous provincial capital, Chengdu. He was only appointed as the province's deputy party boss in September of last year.

Li had also been elected to the party's Central Committee, a ruling council with about 200 full members and 170 or so alternate members, at last month's congress as an alternate member.

(Reporting by Sui-Lee Wee; editing by Jonathan Standing)