Susan Boyle stunned passengers at London's Heathrow airport with a string of bizarre actions.

The 'Wild Horses' singer - who was hospitalised last year for exhaustion amid concern over her mental state - was asked to calm down by officials in the VIP lounge after grabbing a mop from a cleaner, which she then used as a makeshift microphone before trying to polish fellow guests' shoes.

When airline officials intervened, the 48-year-old singer fled the room shouting: "I've escaped, I've escaped."

A source told The Sun newspaper: "It was chaos. Susan was very restless and agitated from the minute she walked in and immediately started making a scene.

"She was singing and dancing around, shouting obscenities at full volume."

The Scottish singer - who shot to fame after appearing on UK TV talent show 'Britain's Got Talent' - was eventually calmed down by a member of airport staff, who sat with her until she boarded her flight to Chicago.

A spokesperson for British Airways said: "A customer in the BA lounge on Tuesday (12.01.10) was asked to temper their behaviour as it was becoming disruptive."

Susan was flying to the US to be a guest on Oprah Winfrey's talk show.