China has hit back at Australia for interfering in its investigation of a Chinese-Australian writer, calling remarks by its foreign minister "irresponsible".
China has told Australia to stop interfering in the lawful investigation of a Chinese-Australian writer and to stop issuing "irresponsible remarks".
Foreign Minister Marise Payne is "deeply disappointed" writer and former diplomat Yang Hengjun has been transferred to criminal detention.
Senator Payne was seeking clarification over the reasons for his detention.
"If he is being detained for his political views, then he should be released," she says.
But a spokesman for China's foreign ministry says Beijing is carrying out a lawful investigation.
"China deplores the statement made by the Australian foreign minister and urges the Australian side not to interfere in China's lawful handling of the case in anyway and stop issuing irresponsible remarks," he said.
The Chinese-born fiction writer, pro-democracy campaigner and former diplomat was being held in Guangzhou after arriving from the US in January.
The 53-year-old, who has held Australian citizenship since 2002 and has a doctorate from the University of Technology Sydney, was living in New York as a visiting scholar at Columbia University.
Australian officials have visited Dr Yang in detention six times, most recently on June 27.
But Senator Payne said despite writing twice to her Chinese counterpart asking for a fair and transparent resolution and for Dr Yang to be allowed to see his lawyers, that had not happened.
"We expect basic standards of justice and procedural fairness to be met."
Friends and family of Dr Yang expect him to be charged with endangering state security.
His Australian lawyer Rob Stary said a political intervention was the only likely means by which to resolve the issue.
He says Australia should use its special relationship with China to secure Dr Yang's release.
Dr Yang's wife, Yuan Xiaoliang, who is a permanent resident of Australia, has been banned from leaving China.
The Law Council of Australia strongly supports Senator Payne's remarks and intervention in this "very troubling matter".
"The Law Council remains concerned that Dr Yang does not appear to have the benefit of any of the traditional safeguards expected of an independent criminal justice system and the rule of law," it said in a statement on Saturday.
This included access to a lawyer of his choice, the right for the public to know what he is being detained for and when it is expected that he will be released.