One first officer was declared incapacitated at 30,000 feet and placed on supplemental oxygen.

The other two flew the Boeing 777-200ER into London Heathrow while developing symptoms of their own. Those symptoms worsened after landing after 10 hours and 30 minutes, and they were assisted by medical staff.

Flight BA276 left Rajiv Gandhi International Airport following an overnight crew layover, according to FlightAware data cited by Fox News.

The three pilots ate breakfast together in the club lounge of their layover hotel on the morning of the flight on July 22, The Sun reported. All three also drank bottled water supplied by an outside provider.

British Airways confirmed to Fox News Digital that one of its pilots became unwell, but the flight’s safety was never compromised.

British Airways Airbus A320 aircraft takes off from Heathrow Airport in London, Britain, May 17, 2021. Photo by Reuters

The airline said it is reviewing crew accommodation in Hyderabad following isolated reports of sickness.

All three pilots filed Air Safety Reports and were asked to provide samples so doctors could establish the cause.

British Airways has not attributed the illness to anything served on board, and no cause has been publicly confirmed.

Crew had lodged “dozens” of complaints about hygiene at the hotel before the flight, union insiders told GB News.

The airline has since moved pilots and cabin crew out of the hotel and booked rooms at a five-star property in Hyderabad’s commercial district, industry site Paddle Your Own Kanoo reported. It is also reviewing crew catering arrangements in the city.

Many carriers require operating pilots to eat different meals in flight, a rule that covers onboard catering rather than meals taken on the ground.