CANBERRA, Australia (AP) — The Australian government says it is "very concerned and disappointed" that a Chinese Australian writer has been formally arrested in China on suspicion of espionage.

Yang Hengjun has been in Chinese custody since he arrived in southern China's Guangzhou from New York on Jan. 19 with his wife Yuan Xiaoliang and his 14-year-old stepdaughter.

Foreign Minister Marise Payne said in a statement on Tuesday that Yang was formally arrested on suspicion of espionage" on Friday last week and "will continue to be criminally detained."

Payne says Yang has been held in Beijing in "harsh conditions" without charge for more than seven months. Since then, China has not explained the reasons for his detention.

Yang's Australian lawyer Rob Stary says it is still unclear what the espionage charge relates to.