Australia has called for the immediate release of academic Yang Hengjun as China confirmed his formal indictment on spying charges.
Dr Yang could face the death penalty if the espionage indictment stands.
"The Australian government is very disappointed that the Chinese authorities have not yet provided formal advice on Dr Yang's indictment," Foreign Minister Marise Payne said in a statement on Wednesday.
"Crises are a time for nations to pull together. It is not in the spirit of mutual respect and trust that our continued advocacy for Dr Yang has not been acknowledged."
Senator Payne said Dr Yang's poor health made him especially vulnerable to COVID-19, a point raised in Australia's most recent representations.
Dr Yang has had no access to legal representation and has been held in harsh conditions.
The last consular visit to him was on December 30.
"This is unacceptable treatment of an Australian citizen," Senator Payne said.
"We call for Dr Yang's immediate release and that he be allowed to leave China and travel to Australia with his wife."
Beijing has a long history of arresting dissidents, including dual nationals.
Melbourne-based lawyer Rob Stary has previously said the allegations against his client are baseless.
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 last year after flying into the country from New York.
He has been detained in Beijing ever since.