Mumbai, Dec 30 (PTI): Sighting of a rat in a London-bound Air India plane by passengers today forced the pilot to abort take off at the city airport, leaving the airline red-faced.

The Air India said "though the presence of the rodent was not confirmed", keeping passenger safety in mind the AI 131 flight returned to the bay and its engineers were investigating the incident. A standby aircraft was made available to fly the passengers to London and the flight left after a delay of six hours.

The flight from Ahmedabad to London via Mumbai was to take off from Mumbai at 1250 hrs but the plane had to be called back right before take off as passengers saw a rat running around in the cabin.

In a statement, the national carrier said "the AI 131 flight from Mumbai to London returned to the bay today due to suspected rat sighting.

"Though the presence of the rodent was not confirmed keeping passenger safety in mind the aircraft was brought back. Our engineering team is investigating the incident."

The aircraft will be fumigated, it said.