CANBERRA, Australia (AP) — The Australian government said on Wednesday it is seeking information about a Chinese-Australian writer who has been reported missing in China.

Novelist and influential online commentator Yang Hengjun was a Chinese diplomat before he became an Australian citizen. Friends say he been living in the United States with his wife and her child and had returned to China late last week.

Australia's Department of Foreign Affairs and Trade said in a statement it was "seeking information about an Australian citizen who has been reported missing in China. Owing to our privacy obligations we will not provide further comment."

Australian consular assistance can include liaising with local authorities, including local police where an Australian has been reported missing.

Yang's friend, University of Technology Sydney academic Feng Chongyi, said he believed Yang was being detained in Beijing by the Ministry of State Security.

"My judgment is based on my information that Yang Jun has been abducted by the personnel of the state security, the ministry of state security and is currently detained in Beijing with his wife," Feng told The Australian newspaper.

Feng was detained in China in 2017 and questioned by security services before he was allowed to return to Australia. Feng had been wrapping up a three-week trip researching human rights lawyers in China when he was detained for several days. He said on his return to Sydney that he was unable to discuss the details of his experience.

Yang's disappearance comes ahead of Defense Minister Christopher Pyne's visit to China. Pyne left Australia on Tuesday for a weeklong visit to Japan, then China and Singapore.

Pyne said the Australia-China defense relationship was a key component of the broader bilateral relationship.

"The government is committed to maintaining a long-term constructive relationship with China, founded on shared interests and mutual respect — China and Australia's success will go hand-in-hand," Pyne said in a statement on Tuesday.

Yang's disappearance also comes a month after China's detention of two Canadians, entrepreneur Michael Spavor and former diplomat Michael Kovrig, which were seen as retaliation for Canada's arrest of Huawei Chief Financial Officer Meng Wanzhou.

Yang, his wife and a child flew from New York on Jan. 18 and arrived in Guangzhou on Jan. 19, Feng said. The wife and child took their next flight Shanghai without him, Feng said.

Feng said he believed Yang and his wife were now both in Beijing, having delivered the child to family and friends in Shanghai.

Former Australian journalist and China analyst John Garnaut said his friend Yang was "not only brilliant but extraordinarily popular among the Chinese-speaking world and a courageous and committed democrat."

"This will reverberate globally if authorities do not quickly find an off-ramp," Garnaut tweeted on Wednesday.

Similar concerns were raised for Yang's safety in 2011 when he disappeared after calling a friend from a Chinese airport claiming he was being followed by three men.

He later explained the matter had been a "misunderstanding."