Friends of the star are worried about her health after she let rip a bizarre four-letter tirade at her niece
Fears over Susan Boyle's mental state are growing, after the singing sensation shouted a tirade of abuse at her niece, in front of shocked onlookers.
The tired Britain's Got Talent star was waiting to board a plane at Heathrow airport when the scene broke out.
An emotional Susan is said to have shouted at her niece Joanne Crawford - who is also her personal assistant - after being informed her private jet, due to take her home, was going to be delayed by two hours.
It's said that SuBo screamed to Joanne that she wanted to 'f****** get home', also calling her 'a bitch'.
In fact some say staff on the jet were even warned to expect arguments between the pair during the flight back to Scotland.
But friends of the star say Susan was simply ‘tired and emotional' after a hectic traveling schedule.
Just last week the singing sensation flew to Japan to perform in front of 10,000 people at the Budokan Arena, before returning home on a grueling 13 hour flight on Good Friday.
An official spokesman added that there was a 'minor' incident between Miss Boyle and Miss Crawford but said: 'Susan is now absolutely fine.'
WATCH SUSAN BOYLE IN ACTION HERE