SYDNEY (REUTERS) - The Australian government is seriously concerned about the detention and welfare of an Australian journalist who has been held in Beijing for one year, foreign minister Marise Payne said on Thursday (Aug 12).

Ms Cheng Lei, who worked as a television anchor for Chinese state media, was formally arrested in February on suspicion of illegally supplying state secrets overseas.

She has been detained since August 2020 and was last visited by Australian consular officials on July 26.

"We are particularly concerned that one year into her detention, there remains a lack of transparency about the reasons for Ms Cheng's detention," Ms Payne said in a statement.

Ms Cheng was a business news anchor on Chinese state media's English-language channel CGTN, where she had worked for almost a decade.

Her children, aged nine and 11, were visiting their grandmother in Australia during school closures in Beijing caused by the Covid-19 pandemic when she was detained.

Australia expected basic standards of justice and humane treatment that met international norms, Ms Payne said.

China's foreign ministry said in February that all of Ms Cheng's rights were being "fully guaranteed".

Federal president of the Australian journalists union, the Media Arts and Entertainment Alliance, Mr Marcus Strom, said Ms Cheng's arrest and the accusations against her have never been explained.

"We urge the Chinese government to drop the charges against our colleague, and to show compassion by allowing her to return to Australia to be with her family," Ms Strom said in a statement.

Ms Cheng was born in China but moved with her parents to Australia as a child and attended university in Queensland state.

Several of her former colleagues at the Chinese state television network, who have since left, told Australian media outlets this week they were shocked by her detention.