Special forces troops are understood to have been involved in the arrest of the suspected Parsons Green bomber at Dover yesterday.
The soldiers are believed to have aided Kent police when the 18-year-old was picked up at 7.50am, minutes before ferries bound for Calais and Dunkirk were due to depart.
Officers were seen talking to the suspect, who appeared calm, for about 10 minutes before the arrest took place.
Dover port was evacuated as a “precautionary measure”. Police were also seen searching bins at Dover Priory station, suggesting the suspect may have arrived by train.
He was taken to a London police station for questioning.