Police briefly detained a man after he attempted to board an aircraft at Gatwick Airport to retrieve a lost wallet, authorities said Wednesday, a day after a 12-year-old boy got on a plane without a ticket or a passport.

The incidents raised new concerns over airport security because the man had managed to bypass heightened security measures at London's second-largest airport.

CountryWatch: Great Britain

The boy was detected by cabin crew before the flight took off.

The man was stopped by police after a cleaner reported a man acting strangely near the plane.

"He was just returning to find his wallet," said an airport spokesman, speaking on condition of anonymity in keeping with departmental policy.