The National Crime Agency said Saturday the 30-year-old man, from London, was arrested Thursday with a 37-year-old Colombian man in a lavatory in Terminal 5 at Heathrow. Officials say the Colombian man had just arrived on a flight from the Colombian capital Bogota.
Another man was arrested in the arrivals airport of the busy international airport and a fourth man was arrested at a London residential address.
All four are being questioned on suspicion of importing drugs.