Bill Clinton is reportedly facing fresh allegations of sexual assault by four women, according to the author of a book on the former president.

Edward Klein, who has written several books on the Clinton family, has claimed Mr Clinton is facing four separate lawsuits by women who are seeking substantial payouts.

The women claim Mr Clinton assaulted them while they were in their late teens and working for playboy billionaire investor Ron Burkle.

Mr Clinton helped the billionaire generate business and reportedly flew around the world with a flock of beautiful young women on Mr Burkle's private jet. There is no suggestion that Mr Burkle was aware of any impropriety.

Mr Klein, the former editor in chief of the New York Times Magazine, has claimed sources within the Democratic party have shared details of the women's intended legal action with him.

It is not clear exactly when the assaults are alleged to have taken place but they date from after Mr Clinton left the White House in 2001, according to the sources.