Three people, including one Briton, were in yesterday court in connection with an alleged plot to smuggle a lethal surface-to-air missile into the US. The precise charges they will face are not known but all three appear to be linked to an apparent attempt to sell an Igla missile to an FBI agent posing as a Muslim extremist. It is thought the alleged target might have been a commercial aircraft or the US President?s personal aircraft, Air Force One. But Washington officials have played down the threat to President George Bush and say there was no credible threat to his plane.

The Briton was arrested at a hotel in Newark, New Jersey on Tuesday, after collecting a package. Two more people were later picked up at a New York gem dealership. The British man, thought to be an established arms dealer, is believed to be a middle aged, married man of Indian origin, who lives in London. Secret services from the US, Russia and Britain were involved in the operation, which began five months ago in St Petersburg.

The sting marks a new phase in cooperation levels between agents in the East and West. A spokesman for the FSB, the Russian secret services, said yesterday it was the first operation of its kind since the Cold War.

Officials claim to have the arms dealer?s voice on tape saying he wanted the missile to be used to shoot down a large passenger plane. No terrorists have been involved in the alleged plot, but three attempts by groups linked to al-Qaeda to shoot down planes carrying Western or Israeli passengers have been foiled in 15 months.

The arms dealer was arrested on suspicion of arranging the purchase at a Russian arms factory, then organising it being shipped to Baltimore, disguised as medical equipment. On Sunday, the man flew to New York with his wife on a British Airways flight from Heathrow Airport in London, two days before his arrest.

The Igla missile, which has a 4 km range and an infra-red capability, was blamed for the shooting down of a Russian helicopter in Chechnya last year. ?This is a deadly missile. They?re coming out with a new version now that can be launched in pairs. If one doesn?t hit the plane, the other will.?