(Bloomberg) -- Writer and former Chinese diplomat Yang Hengjun, who is now an Australian citizen, has been detained by the Chinese government, according to one of his friends.

Yang boarded a flight from New York to the southeastern Chinese city of Guangzhou and was scheduled to arrive at 5 a.m. on Saturday, Feng Chongyi, an associate professor in China studies at the University of Technology Sydney, told Bloomberg News on Wednesday. Yang was then due to catch a connecting flight to Shanghai with his wife and daughter, but he never made through security, Feng said.

The Australian first reported that Yang was feared missing. Asked to confirm that Yang had been detained, a spokesperson for the Australian Department of Foreign Affairs and Trade told Bloomberg News it was “seeking information about an Australian citizen who has been reported missing in China.”

The Chinese Ministry of Foreign Affairs in Beijing didn’t immediately reply to a faxed request for comment Wednesday.

The Sydney Morning Herald reported that Yang hasn’t communicated or posted anything on social media since Friday. Yang had previously worked in the Chinese Foreign Affairs Department in Beijing, before becoming an Australian citizen and a novelist, the Australian newspaper said. He has been living in the U.S. with his wife and stepson and had returned to China late last week, it said.

Feng said he spoke with contacts at the Ministry of State Security, China’s spy agency, and he believes Yang is being held there in Beijing.

The ministry has been in the global spotlight in recent months amid tensions between the U.S. and China. After a top Huawei Technologies Co. executive was arrested in Canada on a U.S. extradition request, MSS agents detained two Canadians in China, sparking a diplomatic feud. It’s been involved in high profile detentions of foreigners and has put dissidents under house arrest without criminal charges.

Feng, who researches human rights, said pressure on the global Chinese diaspora has escalated in recent years. He was detained in China for more than a week in 2017. At the time, his lawyer told the Guardian newspaper that Chinese authorities had cited “national security” in barring him from leaving the country.

--With assistance from Michael Heath, James Mayger, Peter Martin and April Ma.

To contact the reporter on this story: Karen Leigh in Hong Kong at kleigh4@bloomberg.net

To contact the editors responsible for this story: Brendan Scott at bscott66@bloomberg.net, Sharon Chen, Daniel Ten Kate

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