Australian writer Yang Hengjun fears he may die in a Chinese prison without proper medical attention for a troubling kidney condition.
Supporters of Dr Yang said a large cyst on his kidney was causing him pain and urged the Australian government to intervene and secure medical parole for the writer.
Dr Yang said he was frustrated that the truth wouldn't be told if he died in prison.
"If something happens to me, who can speak for me?” he said in a statement issued via friends.
A spokeswoman for Foreign Minister Penny Wong said she shared the deep concerns of his family and friends about the ongoing delays with the case.
Officials from the Australian embassy visited the detained writer last week and have raised concerns about his health.
"The Australian government has consistently advocated for Dr Yang’s interests and wellbeing, and for him to be reunited with his family," the spokeswoman said.
"His case has been raised at every opportunity with the Chinese government, including by the prime minister and foreign minister.
"The resumption of bilateral consular consultations with China last week provided another avenue to discuss his welfare."
Prime Minister Anthony Albanese said he and his ministers "always raise issues of Australian citizens when ... (we) meet with our international counterparts, including China".
Opposition Leader Peter Dutton said Australia should continue to raise human rights abuse concerns with China.
"It's important that we raise issues, particularly where Australian citizens are affected, and particularly where there is a threat to life because of a health condition," he said.
"So, no doubt the prime minister will raise this, as the government should, and we support the government in those efforts."
The foreign minister's spokeswoman said the government had called for basic standards of justice, procedural fairness and humane treatment including medical treatment.
Dr Yang faced a closed trial in Beijing in May 2021 and continues to await a verdict, for which the due date has been extended a further three months to October 9.
The doctor's release remains one of the government's highest priorities as it continues to make progress on the diplomatic relationship with China.
There are hopes that China's new foreign minister will visit Australia by the end of the year after Wang Yi took over from Qin Gang in July.
Senator Wong raised the case with Mr Wang in July.
Mr Albanese is set to visit China, but no date has been announced.