Li was ousted last October after only seven months in the role following a lengthy absence from public view, one of the most prominent examples in a series of high-level disappearances from China's military establishment and political class.

State broadcaster CCTV said in a separate report on Thursday that Li's predecessor, Wei Fenghe, had also been expelled from the party and passed on to prosecutors over alleged corruption.

Chinese President Xi Jinping has waged an unrelenting campaign against official graft since coming to power more than a decade ago.

Proponents say the drive ensures clean governance, but critics argue it also serves as a means for Xi to purge political rivals.

The Communist Party's powerful Politburo of senior leaders ruled on Thursday Li had "betrayed his original mission and lost his party spirit and principles", according to CCTV.

He "seriously polluted the political environment and industrial ethos in the field of military equipment, and caused great damage to the party's cause, national defence and the construction of the armed forces", it said.

- 'Extremely severe' -

Li is suspected of bribery, accused of abusing his position to take "huge sums of money" in return for favours and of bribing others.

He also "illegally sought personnel benefits for himself and others", CCTV said, adding "the nature (of his offences) is extremely severe, their impact was particularly egregious, and the harm from them was particularly huge".

Li's months-long disappearance from public view last year sparked rumours about his political future.

He had travelled to a security conference in Russia in August and days later held a meeting with Belarusian President Alexander Lukashenko, according to handout photos.

However, he then vanished for several months until his removal was confirmed in October.

His sacking followed the dramatic ouster of foreign minister Qin Gang in June last year.

Qin's whereabouts and condition remain unknown, and Beijing's foreign ministry again declined to answer a question about him this week.

- 'Fight and win' -

Xi last week repeated his vow to crack down on graft in the armed forces during an address to a meeting of the Central Military Commission.

He urged China's top brass to "eradicate the soil and conditions in which corruption thrives (and) expand the depth and breadth of the anti-corruption struggle", state media reported.

Xi also called on the military to "strengthen the all-round supervision of senior cadres in exercising their duties and using their powers".

China and its regional neighbours have butted heads in recent months over territorial claims in the hotly disputed South China Sea.

China has also held war games around Taiwan, the self-ruled island that it claims as part of its territory and has vowed to seize one day, by force if needed.

Xi said China's army must "always dare to fight and win", adding that the "situation in the world, country, party and army are undergoing complex and profound changes".