Motor racing legend Sir Jackie Stewart has been taken to hospital after falling ill while flying home from the Geneva Motor Show.
The 71-year-old former Grand Prix star, who was three times world driving champion, was on a British Airways flight from Geneva to London.
BA said its flight crew had requested an emergency landing "so that a male passenger could receive medical attention immediately on arrival".
Journalists on board the flight - BA727 - reported that the pilot asked passengers if there were any medical personnel on the plane, stating that there was a medical emergency.
It was also reported that Sir Jackie got up to go to the toilet during the flight but never returned to his seat and that he was given first aid by stewardesses.
BA said: "Our cabin crew cared for the customer during the flight. We wish him well."
It was understood that Sir Jackie was taken to Hillingdon Hospital in west London after the plane landed at around 12.40pm.
Sir Jackie's son, Paul, told BBC Sport that his father had passed out and as a precaution had been taken to hospital.
He said: "I've just spoken to him in hospital. He seemed absolutely fine but obviously something happened and we need to establish what, but I'm on my way to see him right now. I should think he'll just be checked over and hopefully it will be nothing more sinister than that."
Sir Jackie was the world driving champion in 1969, 1971 and 1973, and won 27 Grand Prix.