Updated

British counterterrorism police investigating an alleged plot to pass classified military information to China have arrested a man in his 70s on suspicion of leaking official secrets.

The Metropolitan Police force says the man was arrested Tuesday in Derbyshire, central England, over an alleged breach of the Official Secrets Act.

The man was taken to a police station before being released under investigation.

The Sun newspaper reports that the man is a former employee of jet engine maker Rolls-Royce and the investigation concerns details of Britain's new F-35 fighter jets.

Police declined to release the man's name or give further details, except that he "worked within private industry."

Asked about the reports Thursday, Rolls-Royce chief executive Warren East said "that's an ongoing investigation and therefore I can't comment."