Chinese-Australian writer Yang Hengjun has been formally arrested on espionage charges in China after months of detention, Australia has confirmed.

The Australian citizen has been held in Beijing since January under “harsh conditions”, said the foreign ministry.

Foreign Minister Marise Payne said Australia was “very concerned and disappointed” to learn of the arrest.

“We have serious concerns for Dr Yang’s welfare, and about the conditions under which he is being been held,” she said.

Mr Yang’s supporters told the BBC that the formal arrest, on 23 August, was an expected but concerning development in his case.

He had been held without charge for more than seven months, during which time Canberra repeatedly pressed Beijing to release him.