Joan Collins is 'completely bald'

Joan Collins is alleged to be completely bald.

The 71-year-old star is said to have been hairless for a number of years but has kept the fact a secret by wearing a wig.

US writer Molly Jong-Fast makes the sensational claim in her new autobiographical book, 'Sex Doctors In The Basement'.

Jong-Fast - whose mother, feminist author Erica Jong, is close friends with Collins - claims she has exposed the former 'Dynasty' star's secret as revenge for taunting her about being overweight when she was just 13.

In one part of the book, the writer says Collins once refused to let her go on a day trip with her and her mother because she was "too fat".

Jong-Fast claims the jibes were so bad she developed bulimia and became depressed about her appearance and her looks.

She said: "Joan should have known obese 13-year-olds turn into menacing 24-year-olds with book contracts. I knew that I would have to turn on her."