Yang Hengjun, a 53-year-old Chinese-born fiction writer, former diplomat and pro-democracy campaigner, has been held in Guangzhou since January after flying into the country from the United States.

Dr Yang, who used to work for China's ministry of foreign affairs but has been an Australian citizen since 2002, was living in New York as a visiting scholar at Columbia University.

His wife Yuan Xiaoliang, a permanent resident of Australia, has been banned from leaving China.

His Australian lawyer Rob Stary says Dr Yang has been moved from Guangzhou to the Beijing public security bureau.

"So the form of his detention has changed. That being the case, we've got an expectation that he's now been charged," Mr Stary told the ABC.

"And the nature of the charge will some breach of internal security."

Mr Stary said Dr Yang is subject to Chinese national law and has been granted limited access to Australian consular officials.

"And we know there was an attempt by the Chinese government to apparently allocate lawyers to him. He wants to engage his own lawyers, which we now understand he's done," Mr Stary said.

The ABC reported on Thursday friends and family say Dr Yang was to be charged with endangering state security - just before a six-month deadline to either charge him, release him or extend his detention.

Australia's Department of Foreign Affairs and Trade said the embassy in Beijing was seeking confirmation from Chinese authorities about Dr Yang's transfer from Guangzhou.

"Australia continues to have consular access and have again asked that he be granted immediate access to his lawyers," a DFAT spokesperson said.

Foreign policy experts and human rights advocacy groups have urged the government to step up diplomatic efforts, with critics arguing its response has not been strong enough.

However, senior Morrison government ministers have said the case has been raised multiple times with the Chinese government.

Earlier this month it was revealed Ms Yuan was questioned by Chinese authorities after trying to leave the country.

She was subjected to an exit ban, but not detained.

Australian Associated Press