Jack Nicholson offered Princess Margaret cocaine, a new book has claimed.

The Hollywood legend allegedly made the illicit drug offer to the British royal - the sister of Queen Elizabeth - at a party held in her honour in Los Angeles, according to a new biography about the life of top Hollywood agent Sue Mengers.

Princess Margaret, who died in February 2002, declined the offer from the Oscar winner and spent much of the night dancing with 'Grease' actor John Travolta at the bash hosted by Sue in 1979.

In the book 'Can I Go Now? The Life of Sue Mengers', author Brian Kellow claims Sue was angered by Jack's actions as she feared he had ruined his chances of ever being invited to Buckingham Palace.

Sue - who died in 2011 - is quoted in the book as saying she made a fool of herself in front of the late princess.

She said: ''Every time she looked my way I curtsied. I was curtsying all night! She thought I was an idiot.''

Princess Margaret died at the age of 71 after suffering a stroke in February 2002. Her death was followed by the death of her mother, the Queen Mother, just a few weeks later.