China's foreign minister Qin Gang was removed from office on Tuesday, state media reported, after not being seen in the public eye for a month.

"China's top legislature voted to appoint Wang Yi as foreign minister... as it convened a session on Tuesday," state media outlet Xinhua said.

"Qin Gang was removed from the post of foreign minister."

The report did not give a reason for Qin's removal but said President Xi Jinping signed a presidential order to enact the decision.

Qin had been seen as a confidant of Xi and many analysts attributed his recent fast rise through the diplomatic ranks to their relationship.

China has remained tight-lipped for weeks about the fate of Qin, who has not been seen in public since June 25 when he met Russia's deputy foreign minister Andrey Rudenko in Beijing.

His absence sparked a storm of speculation that he had been removed from office or was subject to an official investigation.

Qin's duties had lately been taken on by China's top diplomat Wang, who leads the ruling Communist Party's foreign policy and outranks Qin in the government hierarchy.

Qin had replaced Wang as foreign minister in December last year.