Animal rights campaigners Sir Paul McCartney and his wife Heather believe UK high street shoppers could be unwittingly purchasing real fur.

A BBC documentary found that as there is no legal requirement to label fur garments, some people may not know what they are buying.

In the programme, broadcast last night, the couple, who have a home in Hove, continue to fight to curb the market for fur products.

They have been outspoken in their criticism of high-profile celebrities who wear fur, and campaign vigorously against the trade in dog and cat fur.

Sir Paul admits he wore fur when a member of The Beatles, but says he did not realise what he was doing.

He says: "Like most people we didn't realise when you wore a fur jacket, as John did on the concert tour on the roof of Apple, or as I did in the film Help... you didn't realise what you were doing by wearing fur."

His wife, Heather Mills McCartney, was followed as she protested at fashion stores, including Jennifer Lopez's Sweetface label in New York.

The programme, Real Story: McCartneys Versus Fur, looked at the £7 billion global fur industry. It followed Mrs Mills McCartney to a Peta (People for the Ethical Treatment of Animals) gala in the United States, and to Brussels, where she appealed for a European ban on cat and dog fur.

She is the face of a Peta antifur advertisement campaign which carries the slogan: "If you wouldn't wear your dog, please don't wear any fur."