Joan Collins is obsessed with wigs.

The 80-year-old actress has been wearing wigs for over 30 years, and she doesn't understand why there is a negative stigma attached to fake hair pieces when extensions are so widely accepted.

She told the new UK issue of HELLO! magazine: ''I love wigs. It's ridiculous that extensions are acceptable on practically every actress and model yet some people turn their noses up at wigs.''

The star - who has worn fake hair since the 1980s when she first appeared on hit TV show 'Dynasty' - dons a red wig for her latest role in 'Molly Moon: The Incredible Hypnotist', where she plays a crime leader.

She explained: ''It was so much fun to film. In one scene I spent the entire day scrambling out of an armoured truck filled with gold bars wearing the boots, skin-tight black leather trousers and a long red wig. ''

Joan - who is married to theatrical company manager Percy Gibson - wears her sexy outfit with confidence and thinks most people her age would not be as brave.

She said: ''I said to the director, 'You know most actresses over 40 couldn't do this.' ''