Concerned colleagues, who had smelled alcohol on the pilot, called the emergency services amidst fears over the safety of the 300 passengers on board.
As passengers and crew looked on, armed police boarded the plane and eventually led the pilot away in handcuffs.
The pilot is described as a 49 year old man from Harmondsworth in West Drayton.
A spokesperson for BA apologised to passengers, letting them know that the matter was being taken extremely seriously.
The flight eventually left for Mauritius following a delay of approximately 3 hours.