Passengers on a flight to Tenerife were forced to cross their legs for more than three hours after cabin crew discovered an issue with the on-board toilets.
British Airways (BA) apologised to customers on the 9.05am flight on Wednesday, which left around half an hour after its scheduled departure from London Gatwick, after it was forced to touch down in Portugal, the airline said.
According to air traffic tracker Flight Radar, the flight made an almost 180 degree turn as it was diverted to Faro airport, landing at approximately 1pm.
The plane went on to Tenerife, with knock-on delays of more than two hours for passengers on the returning flight to London.
BA said there was "very little disruption" to customers and the plane was only on the ground for half an hour.
It did not say what took place during the brief stop, nor whether the issue was due to toilet checks not being done before take-off or whether a separate problem was discovered while airborne.
A spokeswoman said: "We got our customers on their way to their destination in just over half an hour, and said sorry for the delay to their journeys."