Australia's peak lawyers association has urged the government to confront China over its detention of a prominent human rights lawyer.

The president-elect of the Law Council of Australia Arthur Moses wrote to Foreign Affairs Minister Marise Payne asking her to make "immediate diplomatic representations to China regarding human rights lawyer Wang Quanzhang".

Mr Wang defended political activists and victims of land seizures before disappearing in a 2015 sweep, known as the "709" crackdown, aimed at courtroom critics of Communist authorities.

Getty

The Law Council claims Mr Wang has been detained since then "without contact with his family and reportedly without legal representation for much of this time".

He had a one-day trial in a closed court earlier this week and will reportedly be sentenced at a later, undetermined date.

In the letter, Mr Moses said the matter was "urgent and grave".

"The Law Council believes that Australia has an important role to play in promoting and defending the rule of law and human rights in the Asia-Pacific region," he said, urging Ms Payne to help "ensure a fair and transparent trial for Mr Wang".

He said the Law Council was "acutely troubled by reports that lawyers seeking to represent Mr Wang had been menaced and discouraged".

"Legal representation must be available to every citizen, not just the powerful or the popular."

READ MORE China rights lawyer trial held behind closed doors as activists detained

"In accordance with the United Nations' Basic Principles on the Role of the Lawyers, it is vital for every nation to have an independent legal profession that can practice without fear of reprisal. This is critical to ensure that not only is justice done, justice is seen to be done."

After Mr Wang was charged in January with the "subversion of state power", he was not heard from until his court-assigned lawyer contacted his wife on Monday to say his trial would be held in the northern city of Tianjin two days later.

SBS News contacted the office of Ms Payne for comment on the Law Council letter but has not received a reply.

AAP

Earlier this week, Amnesty International called the trial a "cruel charade".

"This is a sham trial in which Wang Quanzhang is being persecuted only for peacefully defending human rights," said Doriane Lau, a China researcher at Amnesty International.

"Wang Quanzhang has already been unjustly held for more than three years, during which his family suffered the anguish of not knowing whether he was alive until recently. He must be immediately and unconditionally released."

'Concern' over Canadians

On Monday, the Australian government did speak out over two other individuals detained in China - Canadian citizens Michael Spavor and Michael Kovrig.

The two Canadians were detained in early December, days after Canadian police arrested Huawei chief financial officer Meng Wanzhou in Vancouver.

AAP

Ms Payne said officials had been in touch with counterparts in Canada and shared Australia's position on the detentions with Chinese diplomats.

"The Australian government is concerned about the recent detention of two Canadian citizens in China," Ms Payne said in a statement.

"We would be very concerned if these cases were related to legal proceedings currently underway in Canada involving a Chinese citizen, Ms Meng Wanzhou.

"The Australian government has conveyed this position to Chinese counterparts and we have been in regular contact with Canadian officials."

AAP

The US, Britain and European Union issued statements showing support for Canada about 10 days ago, after it called for its two citizens to be immediately released.

Mr Spavor and Mr Kovrig are accused of harming China's national security, while Ms Wanzhou is wanted by the US over fraud charges linked to the alleged evasion of sanctions on Iran.

Additional reporting: AAP, AFP