Australian diplomats have been denied access to the Beijing court where Australian citizen Yang Hengjun is being tried for espionage.

The 56-year-old writer and former employee of China’s state security ministry is going on trial for espionage, more than two years after agents swooped on him as he arrived at a southern Chinese airport.

Chinese authorities have not publicly provided any details about what Dr Yang is alleged to have done.

Australia’s ambassador to China Graham Fletcher said he was barred from entering because of COVID-19 restrictions, and because it was a national security issue.

“This is deeply regrettable, concerning and unsatisfactory,” he said outside the court.

“We’ve had longstanding concerns about this case including lack of transparency and therefore have concluded it’s a case of arbitrary detention.

“Regardless of what happens today we will continue to advocate strongly and continue to provide consular support to his family”.

One of his Beijing-based lawyers, Shang Baojun, declined to provide any details about the case to the ABC.

Dr Yang’s wife Yuan Ruijuan, who is in Beijing, said she was also in the dark.

“It’s a closed-door trial, so aside from the lawyers and prosecutors, no-one else will know what’s going on in the courtroom,” said Ms Yuan.

“I’m very much anticipating this trial because my husband will finally have a chance to prove his innocence.

“But I’m quite nervous and worried about the trial because given the current state of Australia-China relations, it’s very hard to be optimistic.”

Ms Yuan told the ABC she expected she would be able to see her husband for the first time in two-and-a-half years once he had been sentenced.

Ms Yuan hopes she will finally be able to see her husband after he is sentenced. Photo: ABC

Dr Yang claims China ‘taking revenge’ on him

Ahead of the trial, supporters released a letter written by Dr Yang from his prison cell, in which he suggested the case was “revenge” for his outspoken online writings about Chinese politics.

He also said he was “spiritually strong” and vowed to “face suffering and torture with resilience”.

The letter also alluded to his past working for China’s state security agencies, describing Hong Kong as a “place where I worked for six years for the Chinese government”.

Dr Yang’s supporters say since leaving the Chinese system in the late 1990s, he decisively turned his back on it.

He later moved to Australia and obtained citizenship before completing a PhD at the University of Technology in Sydney.

He had returned to China for visits multiple times and was living in the US as a visiting scholar at Columbia University in 2019 when he flew into China for the Lunar New Year and was detained upon arrival.

He has spent the past two years and four months locked in a prison in southern Beijing, undergoing hundreds of interrogations and writing letters proclaiming his innocence.

Chinese authorities made him wait 19 months before granting him access to a lawyer and did not allow any family or other visitors to see him.

Foreign Affairs Minister Marise Payne asked China to grant Australian diplomats access to the trial. Photo: ABC

Australian diplomats barred from court

A number of Australian diplomats arrived outside the Beijing No.2 Intermediate Court but were not allowed inside the building to observe proceedings.

The Chinese government last week labelled a request for access by Foreign Minister Marise Payne as “deplorable” in an English statement, although it was toned down to “regrettable” in the Chinese version.

Speaking on AM ahead of the trial, Ms Payne declined to speculate on whether diplomats would be allowed to observe the trial.

“I very much hope Dr Yang is provided with a fair trial, but we have not seen any explanation or evidence of the charges brought against him,” she said.

ANU legal expert, Donald Rothwell, said an existing agreement Australia had with China should have ensured access for consular officials regardless of the allegations.

“China has a clear obligation under the Consular Agreement to permit Australian officials to attend the Yang trial,” he told the ABC.

“The right of Australian officials to attend [Dr] Yang’s trial exists irrespective of any claims China may make that the trial is closed on national security grounds or COVID-19 restrictions.”

In March, China’s government denied Canadian diplomats access to the espionage trials of two of its citizens, citing national security.

-ABC