Australian journalist Cheng Lei has been formally arrested on suspicion of spying after being detained without charge by Chinese officials for more than six months.
Foreign Minister Marise Payne told reporters on Monday that Chinese officials had advised the Australian government of Ms Cheng's arrest "on suspicion of illegally supplying state secrets overseas".
The popular journalist and television presenter was suddenly detained on 13 August last year and later accused of broad "national security" offences.
"The Australian Government has raised its serious concerns about Ms Cheng’s detention regularly at senior levels, including about her welfare and conditions of detention," Senator Payne said in a statement.
"We expect basic standards of justice, procedural fairness and humane treatment to be met, in accordance with international norms.
"Our thoughts are with Ms Cheng and her family during this difficult period."
Consular officials have visited Ms Cheng on six occasions, with the most recent meeting taking place on 27 January, she said.
Ms Cheng, who is an Australian citizen, was working as a business anchor for state-run Chinese broadcaster CGTN before she was taken into custody.
For the past six months, it is understood she has been held in what Chinese authorities call "residential surveillance at a designated location" - .
Last year, Sydney academic Chongyi Feng - who himself was detained by Chinese authorities for a week in 2017 -, including constant surveillance by secret service officers, marathon interrogations, and torture.
The details of the allegations against Ms Cheng are still unclear, with Chinese officials previously stating she is “suspected of carrying out illegal activities endangering China’s national security”.
Senator Payne said it was likely the formal investigation stage of Ms Cheng's case could take several months.
"We will continue providing the strongest consular support to her as possible and engage as strongly as we are able to with Chinese authorities in relation to her detention," she told reporters.
Ms Cheng, who was raised in Australia and studied at the University of Queensland, had worked at CGTN for eight years following stints at CNBC Asia in Singapore and China and at CGTN's predecessor, CCTV News.
She has been described as a "bridge between China and Australia" who used her connections to both countries to further bilateral relationships and someone who was .
“Why her, why now? She hasn’t really done anything extraordinary. She’s not overly outspoken about the political situation in China,” Delia Lin, a senior lecturer in Chinese Studies at Melbourne University, told SBS News following Ms Cheng's detention.
In an exclusive interview with the ABC's 7.30 program, , Ms Cheng's family reportedly said they were in the dark about the reasons for her arrest, breaking their almost six-month silence on the case.
"Every time we do something fun, we're thinking of her and how she can't enjoy these things with us," Ms Cheng's niece Louisa Wen reportedly told 7.30.
"We don't know if she's just been caught up in something that she herself didn't realise."
The last two Australian correspondents based in China - the ABC's Bill Birtles and the Australian Financial Review's Michael Smith - last year after being questioned by Chinese authorities about the investigation into Ms Cheng.
Another Australian citizen, Yang Hengjun, has so far spent more than two years detained in China also accused of national security offences.
The 55-year-old writer and commentator was and is currently awaiting trial.
