Free Australian from solitary, China told

Foreign Minister Marise Payne is calling on China to release Australian writer Yang Hengjun from solitary confinement in Beijing.

Dr Yang has reportedly been shackled in chains and told he could face the death penalty if convicted of spying.

"His circumstances of detention are very, very concerning to us," Senator Payne told ABC radio on Wednesday.

"We have asked for him to be given access to his lawyers, and I repeated that request in recent days to my counterpart, state councillor Wang Yi."

Australia is also lobbying China to ease the harsh conditions Dr Yang is being held in.

"We have asked for him to be given access to family visits and to be released from what appears to be a version of solitary confinement, which gives him very little access to the outside world," Senator Payne said.

"It's the case that we understand his movements have been very tightly constricted, so they are all concerning circumstances for us."

Consular officials visited Dr Yang in Beijing last month.

"We will continue to press for all of those issues to be addressed and ask that he be treated in international human rights law and expectations," Senator Payne said.

Dr Yang is a former Chinese diplomat who went on to become a pro-democracy campaigner and was made an Australian citizen in 2002.

He was detained in January after flying into China from New York, where he was living with his family and working as a visiting scholar at Columbia University.

Prime Minister Scott Morrison has previously described suggestions Dr Yang was a spy for Australia as "absolutely untrue".