The United Airlines plane was due to take off from Heathrow Airport

A United Airlines pilot was arrested on suspicion of being drunk on board a plane at Heathrow Airport on Monday, a Scotland Yard spokesman has said.

The 51-year-old, who has not been named, was breath-tested and taken to London's Heathrow police station.

The plane's departure to Chicago was "imminent", with 124 passengers and 11 crew members on board, when the arrest took place, a Heathrow spokesman said.

Passengers were put on to other planes after the flight was cancelled.

'Strict policy'

A Metropolitan Police spokesman said: "At 12.30pm on 9 November we attended a flight at Heathrow Airport and arrested a 51-year-old man.

"He was arrested on suspicion of being aviation staff performing an aviation function while exceeding the prescribed alcohol limit."

Police are awaiting the outcome of further tests on the man.

"He was reported to police by United Airlines staff, said a BAA Heathrow spokesman.

A United Airlines spokeswoman said: "Safety is our highest priority and the pilot has been removed from service while we are cooperating with authorities and conducting a full investigation.

"United Airlines' alcohol policy is amongst the strictest in the industry and we have no tolerance for violation of this well-established policy."