According to an indictment unsealed by a U.S. court, former U.S. Marine Daniel Duggan, who was detained in Australia, is accused of violating American weapons control law by instructing Chinese military pilots to land on aircraft carriers.

Through a South African flight school, Duggan allegedly “offered military instruction to PRC (People’s Republic of China) pilots” on three occasions between 2010 and 2012.

It lists unnamed co-conspirators including one South African and one British national who were executives of “a test flying academy based in South Africa with a presence in the PRC”, and a Chinese national who acquired military information for the Chinese military.

Britain announced a crackdown on its former military pilots working to train Chinese military fliers the same week Duggan was arrested in Australia.

Australian police provisionally arrested Duggan in the rural town of Orange at the request of the U.S. government in October, pending an extradition request by the United States.

Duggan’s lawyer, Dennis Miralis of Australian law firm Nyman Gibson Miralis, did not immediately respond to a Reuters request for comment on the indictment.

He has previously said Duggan denies breaching any law, and is an Australian citizen who had renounced his U.S. citizenship.