Passengers were left surprised after a flight from Italy to London Gatwick was diverted to Northern Africa.
The commercial flight had been due to depart from Lamezia Terme airport in southern Italy around 11am on Saturday.
After the flight took off, passengers were warned that it would be making an unscheduled diversion southwest to Tunisia.
The Boeing 737 made the temporary stop in order to deliver a part for another aircraft at Enfidha airport on the Tunisian east coast.
Passengers were forced to wait for an hour so that the part could be dropped off and the plane refuelled before a three-hour flight to Gatwick.
The plane arrived at the Sussex airport almost four hours late due to the 400-mile detour.
A spokesperson for Tui said: “We can confirm that flight BY4651 made a short stop at Enfidha-Hammamet Airport in order to drop off equipment required at the airport for another aircraft.
“The equipment was for the TOM529 aircraft, which suffered a technical issue prior to its departure, and needed engineering support.”
The spokesperson added: “We’d like to apologise again for any inconvenience caused and thank customers for their patience and understanding.
“All customers were given a complimentary drink on board as a gesture of goodwill and all will be entitled to claim EU261 flight delay compensation.”
