Sun, 53, a politburo member, was once regarded as a frontrunner to the key policy body of the ruling Communist Party of China (CPC).
He has also been stripped of all official titles, two months after his shock downfall and just weeks before a key five-yearly leadership reshuffle, the report said.
His expulsion comes ahead of the 19th CPC Congress which is expected to endorse a second five-year term for Chinese President and party leader Xi Jinping.
Thousands of officials have been punished in the massive anti-corruption campaign launched by Xi who has also faced allegations of effectively using the drive to consolidate his hold over the party and the government in his first term.
The investigation found that Sun had betrayed party principles and lost political stance, ignoring the party code of conduct and rules, Xinhua quoted an official statement as saying.
Sun, once seen as a frontrunner for a seat in the political inner sanctum, the Politburo Standing Committee, was unceremoniously removed as Chongqing’s party boss and put under investigation by party graft-busters in July for “serious violations of party discipline”, Hong Kong-based South China Morning Post reported today.
He was also found to have seriously violated the CPC eight-point code on frugality and maintaining close ties with the masses, sought pomp, ostentation and privileges and guilty of nepotism and seeking benefits in selection of officials.
He was also found guilty of leaking confidential party information and seriously breaching party rules on integrity, took advantage of his power and influence and sought substantial benefits for his relatives’ businesses and accepted valuable gifts, Xinhua said.
The announcement of his expulsion from the party means he will also be removed from the 25-member politburo, the party’s powerful decision-making body.
Sun had been handed over to judicial authorities for further investigation, the report added.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)