After the American Airlines flight touched down at Heathrow, the man, his mother and his two sisters were questioned by Special Branch officers then released without charge.

Yesterday, as American Airlines completed arrangements for the other 236 passengers to reach the United States, police said that the man was not wanted in Britain and of “no interest” to counterterrorist officers.

He was flying to Boston on Monday on Flight 109, a Boeing 777 with 240 passengers and 13 crew, but two hours into the flight the captain was told to go back.

Darrin Kayser, a spokesman for the US Transportation Security Administration (TSA), said yesterday: “Early in the flight TSA learnt that a passenger on board was on the no-fly list. TSA determined that the best course of action was to turn the flight around.” He said that American Airlines and air traffic control were in regular communication with the flight and “there were no reports of unusual activity”.

Yesterday neither the airline nor the transport authority would discuss the reasons behind the decision.

Times Recommends

• Michael Jackson: Not the final chapter
• Indian Army spends10m rupees on golf buggies
• Brüno toned down for 15 rating