A British Airways flight to Dubai was forced to return to Heathrow when the smell from a toilet reportedly became unbearable for passengers.
The pilot announced that the flight had to be aborted after cabin crew were unable to prevent the smell emanating from an overflowing toilet.
The aircraft returned to London around 30 minutes in the seven-hour flight, amid health and safety concerns.
The captain said the crew had investigated the problem but were unable to fix it, so the aircraft would have to return to London.
The flight took off at 8.15pm on Thursday night and was due to land in Dubai seven hours later.
Instead, passengers had to wait 15 hours before they could resume their journey, catching another flight to Dubai at 1pm on Friday.
Hertsmere councillor Abhishek Sachdev, who was on the aircraft, tweeted to say it was “insane” that passengers had to wait 15 hours for another flight due to a “smelly poo in the toilet”.
He told Mail Online: “The pilot made an announcement requesting senior cabin crew, and we knew something was a bit odd. About 10 minutes later he said you may have noticed there’s a quite pungent smell coming from one of the toilets.”
Sachdev, who was not seated near the toilet in question, said: “He said it was liquid faecal excrement, those are the words he used.
“He said it’s not a technical fault with the plane, and he was very adamant about that.”
A BA spokesman said: “We’re very sorry for the discomfort to our customers. We provided them with hotel accommodation and rescheduled the flight to depart the next day.”