Naomi Campbell allegedly threw a huge tantrum at an airport yesterday after she wasn't allowed to board her flight.The supermodel - who recently had to attend anger-management classes - turned up 11 minutes before her flight was due to take-off from London's Heathrow and demanded to be let on.Onlookers claim the 37-year-old star stamped her feet and whined: "You have to let me on. Come on."British Airways staff said she was too late but did offer to let her travel without her luggage and send her bags on a later flight.But Naomi yelled: "You are joking. You are always losing bags and I don't trust you with mine in a million years."I can't believe you won't allow ME on your flight. What is this? Who must I speak to?"A source told Britain's Daily Mirror newspaper: "When BA staff explained she was too late, she exploded and stamped her foot. There was a tirade of abuse."Naomi - who arrived in chauffeur driven car at 13.29 even though her flight to New York was due to take off at 13.40 - was offered a seat on a later BA flight, but she reportedly stormed off.Last night, a spokesman for Naomi insisted there was no problem with her getting a flight, saying: "She is in the air at the moment, travelling to New York on business. We are not aware of any incident."