A Chinese-born Australian writer held in China since January has been charged with espionage, his lawyer and the Australian government said on Tuesday, amid growing tension between Canberra and its largest trading partner. Yang Hengjun, a former Chinese diplomat turned online journalist and blogger, was detained in the southern city of Guangzhou while waiting for a transfer to Shanghai, after flying in from New York. He was later moved to the capital Beijing. "Dr Yang has been held in Beijing in harsh conditions without charge for more than seven months," Foreign Minister Marise Payne said in a statement, adding Yang was formally arrested on suspicion of spying last Friday. Espionage is punishable by death in China. The arrest of Yang, 53, whose legal name is Yang Jun, comes as Beijing struggles to contain anti-government protests in Hong Kong, the semi-autonomous Chinese city. There was no immediate response from China's Foreign Ministry. The Chinese embassy in Canberra did not immediately respond to requests for comment. Yang's wife, who is an Australian permanent resident, has also been barred from leaving China. China has not allowed Yang access to his lawyers or family since his detention, Payne said. Yang's Australian lawyer, Robert Stary, said Yang faced one charge of espionage, which Yang intends to deny, but the basis of the charge was unknown. "We don't know for instance, whether it's as a consequence of his writings as a democracy activist, or a blogger or an academic," Stary told Reuters. "He'd spent long periods in the U.S. So we don't know whether it's suggested he's spying for Australia, or the U.S., or Taiwan or whoever it might be, if that's the allegation." Stary said he wants the Australian government to press for Yang's release if there is no other evidence against him other than the fact that he is a pro-democracy activist. Stary has briefed a prominent Australian barrister, Julian McMahon, to represent Yang, hoping he will be able to work with Yang's Beijing court-appointed lawyer. Human rights activists urged Canberra to press for Yang's immediate release. -Reuters