Australian police provisionally arrested Duggan in the rural town of Orange at the request of the US government in October, pending a likely extradition request by the US.

That same week Britain announced a crackdown on its former military pilots working to train Chinese military fliers.

The district of Columbia court on Friday unsealed the indictment and a US warrant for Duggan’s arrest because it said he had been arrested.

Duggan is being held in custody in Sydney and his case will return to a Sydney court this week.

The US must lodge an extradition request for Duggan by Dec 20 under a bilateral treaty.

Duggan faces four charges, including conspiracy to defraud the US by conspiracy to unlawfully export defence services to China, conspiracy to launder money, and two counts of violating the arms export control act and international traffic in arms regulations.

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

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

“He denies having breached any US law, any Australian law, any international law,” Miralis said outside a Sydney court last month.

Duggan moved to Australia after a decade in the US marines, later moving to Beijing in 2014 where he worked as an aviation consultant.

He had returned to Australia from China weeks before he was arrested, his lawyer said previously.