Foreign Minister Marise Payne is focused on the welfare of Chinese-Australian writer and academic Yang Hengjun as she endeavours to seek his release.

"I do think it is extremely important - and we have been at pains to say - he should be afforded access to his lawyers," Senator Payne told reporters in Sydney on Wednesday.

"He should be afforded the opportunity to communicate with his family.

"They are reasonably basic entitlements, and we would seek to prosecute that case."

Dr Yang could face the death penalty if spying charges against him stand.

Victorian barrister Julian McMahon - who worked pro-bono attempting to save two Australian members of the Bali Nine from the death penalty - has recently joined the case alongside Melbourne lawyer Rob Stary.

Mr McMahon says it could be months before details of the broad spying allegations are known.

Unlike the Australian system, people in China are detained, arrested and charged in three separate steps.

"The problem we have at the moment is that although our client has been detained, we don't have material, we don't have the basis of the detention except a vague allegation," he said.

"And we don't have the timetable."

But Mr McMahon understands Dr Yang is in good spirits.

Senator Payne has reminded China it must comply with international laws banning torture, inhumane treatment and arbitrary detention.

She has described as "harsh" the conditions of Dr Yang's detention for the past seven months.

"We want to make it very clear that under no circumstances should an Australian citizen be exposed to any treatment of that sort," the minister said.

China has warned Australia to respect its sovereignty and not to interfere in the case.

"China is a country with rule of law and Australia should earnestly respect China's judicial sovereignty and stop interfering in China's case-handling in any form," foreign ministry spokesperson Geng Shuang said.

Beijing has a long history of arresting dissidents, including dual nationals.

Australia's travel advice for China was updated in April, following the arrest, to note: "China's laws on national security are interpreted broadly."

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

The 54-year-old was detained in Guangzhou in January after flying into the country from New York where he was living with his family and working as a visiting scholar at Columbia University.

Embassy officials visited Dr Yang in detention on Tuesday, and Senator Payne is awaiting an update.

The Law Council of Australia stands ready to provide any assistance required.

"In China, espionage is punishable by death," president Arthur Moses told AAP.

"The Law Council decries capital punishment and, as previously seen in other cases involving Australians facing the death penalty in other parts of the world, there is a dire need for early government intervention."

He also has a doctorate from the University of Technology in Sydney.

Australian Associated Press