NSW academic returns after China drama

A Sydney-based academic who was detained in China for what Beijing described as national security reasons has returned to Australia.

Associate professor Chongyi Feng, who has previously spoken out against China's ruling Communist Party "shutting down speech" and was in China researching human rights issues, was barred from flying to Australia from Guangzhou with his wife just over a week ago.

He faced several rounds of questioning from authorities but was never arrested or charged with any offence.

Former foreign minister Bob Carr made representations in Beijing and Canberra about Dr Feng's case while the University of Technology Sydney (UTS) appealed to the Chinese Consulate in Sydney to negotiate his release.

On Sunday, he told reporters he wasn't sure why he was released, but suspected international pressure from the media, government and his university had played a role.

In a statement, UTS said it was pleased the matter had been resolved.

"The university will continue to provide care, as his employer, to Dr Feng and his family in relation to his recent experience," it said in a statement.

Dozens of internationally-respected academics from Australia, the United States, Britain and Hong Kong penned an open letter addressed to Chinese President Xi Jinping and Prime Minister Li "respectfully requesting" the academic's release.

The letter said they were "disturbed" that a fellow researcher was "prevented from returning to his home and workplace for no reason other than his conscientious work" as a China Studies scholar.

Dr Feng is an Australian permanent resident who retains his Chinese passport.

A spokesperson for the Department of Foreign Affairs and Trade said the federal government welcomed the news of Dr Feng's return.