The celebrity chef went to Heathrow on Sunday morning to take a British Airways flight to Los Angeles. It is understood that the domestic goddess checked in and cleared security when she was told she could not fly, The Daily Mail reported.
"She didn't seem to say much, but she did not look happy. She could not get on the flight so she had to turn around and leave," a witness told the paper.
CLICK ON PHOTOS FOR FULL GALLERY
The star was forced to return to the first class check-in to collect the luggage that she had planned to stow in the hold.
The celebrity cook was due to fly to LA to act as a judge on TV cooking show The Taste, but was turned back following the revelation that she had taken drugs several times in a court case back in November.
Despite the controversy surrounding the public trial, Scotland Yard decided not to take the confession further.
Nigella with fellow judges on the UK's The Taste
But it has surfaced now that Nigella has attempted to travel to the US. America reserves the right to ban visitors entering the country if they have admitted to drug use, even if they have not been convicted.
The mum of two is believed to have registered online for permission to travel to the States, where travellers must confirm that they have not been arrested or convicted of offences, including taking illegal drugs.
The day before her scheduled trip, Nigella posted a photo on Twitter showing her excitement at heading Stateside. "Packing for my holiday! #essentials" she wrote alongside the snap, which showed a sunhat, a tube of Colman's Mustard and a small tin of Maldon sea salt.