A US jury has accused two foreign nationals of trying to buy military aircraft engines and weapons to export to China.
They pair are alleged to have tried to buy F-16 engines
A Miami jury also charged one of the suspects, Ko-Suen Moo, of Taiwan, with being a covert Chinese agent and offering a bribe to escape custody.
Mr Moo was arrested in Miami in November 2005.
A French national, Maurice Serge Voros, was also charged in the indictment. He remains at large.
According to the nine-count indictment, Mr Moo and Mr Voros sought to acquire an F-16 engine, Blackhawk helicopter engines and cruise missiles early last year.
They are alleged to have initially sought to buy and ship 70 Blackhawk engines to China, but that Mr Moo decided to acquire the jet engine as a priority.
The indictment says the defendants violated the US Arms Export Control Act by attempting to export the items without a licence.
Mr Moo has been in custody in Miami after being charged in an earlier grand jury indictment. He has pleaded not guilty to the illegal export charges.
The new indictment brought the agent and $500,000 bribery charges against Mr Moo and also added Mr Voros to the case.
The US has repeatedly expressed its concern at the amount of money China is spending on its military, and has warned it could soon alter the military balance in the Asia-Pacific region.
Washington is particularly concerned about a build-up of Chinese missiles pointed at Taiwan, which Beijing has threatened to seize by force if the island moves towards formal independence.
This could quickly embroil the US, which has given security assurances to Taiwan.