CANBERRA, Australia -- Australia's foreign minister on Thursday urged China to treat a Chinese-Australian writer fairly and transparently, adding there was no evidence that his detention almost a week ago was part of a backlash against Canada's arrest of a top Chinese telecommunications executive.

Spy novelist and online commentator Yang Hengjun was a Chinese diplomat before he became an Australian citizen. Friends say the 53-year-old had been living in New York as a visiting scholar at Columbia University and had returned to China last week with his wife, Yuan Rui Juan, and 14-year-old stepdaughter.

Foreign Minister Marise Payne said Australian Embassy officials had their first meeting with Chinese officials in Beijing on Yang's detention on Thursday. Australia had requested consular accesses to him, an explanation for his detention and of the possible charges.

Payne said the government would be concerned if the detention was related to China detaining two Canadians last month or her government's decision in August to block Chinese telecommunications giant Huawei from rolling out Australia's 5G network due to security concerns. Both issues have figured in speculation about the reasons for Yang's detention.

"At this stage there is no evidence of such a connection," Payne told reporters of a potential link to the Canadians' detention.

"I'd be concerned if there was an indication of that. So we are calling on the Chinese authorities to ensure this matter is dealt with transparently and fairly," she added.

Opposition leader Bill Shorten, who opinion polls suggest will become prime minister at general election due by May, criticized China for failing to notify Australia within three days that an Australian had been detained, as stipulated by a bilateral consular agreement.

"It's surprising and concerning," Shorten told reporters

Payne declined to make public details of where and when Yang had been detained. She said she wanted an explanation for why Australia was not informed until Wednesday night after Yang's friends and family had raised the alarm that he was missing.

Defence Minister Christopher Pyne told reporters at the start of his visit to Beijing on Thursday that Yang was being held in a type of home detention in Beijing.

Pyne said he intended to raise the case in his meetings with Chinese officials.

"The Australian government is obviously concerned with the residential surveillance of Mr. Yang," Pyne said. "I have no further and better particulars on the reasons for Mr. Yang's detention or what the plan is for Mr. Yang, but obviously we are seeking that information."

Yang's friend, University of Technology Sydney academic Feng Chongyi, said he believed Yang was detained on suspicion of espionage since Saturday.

The detention comes a month after China's detention of two Canadians, entrepreneur Michael Spavor and former diplomat Michael Kovrig, in what was widely seen as retaliation for Canada's arrest of Huawei Chief Financial Officer Meng Wanzhou at the request of the United States.

Feng said he had warned Yang against travelling to China in light of the Canadians' arrest. Yang had argued that he was safe because he had flown to China several times since taking the university job in New York in 2016.

"I told him the situation had changed. He didn't believe me. It was a horrible misjudgment," Feng said.

Feng was detained for two weeks in 2017 while visiting China to research human rights lawyers and said later that he couldn't discuss details of his experience.

Rory Medcalf, head of the Australian National University's National Security College, had warned after the Canadians were detained that an Australian could be the next victim of "China's hostage-taking."

"It's hard to tell the precise reason for this detention," Medcalf said. "I think rather it's a signal that we're now -- not only Australia, but really all democracies, all middle powers -- are in for a period of sustained tension with China where the safety of our nationals in China simply cannot be assured."

Columbia University said Yang had been a visiting scholar with the School of International Public Affairs' Institute for the Study of Human Rights since 2016. Spokeswoman Caroline Adelman said the university had no comment on Yang's detention.