'Guinness is just an old friend': McCartney

Paul McCartney has dismissed reports he is dating Sabrina Guinness - insisting she is just an "old friend".

The former Beatle was spotted with the 52-year-old - a former girlfriend of Mick Jagger and Prince Charles - in London on Wednesday evening.

But McCartney has denied claims he is romantically linked to the Guinness drinks empire heiress since splitting from Heather Mills last year.

He says: "It's nothing more than friendship. I realise everyone wants to see me with a new bird right now, and that's really flattering.

"I have had a terrible day at the office and as you probably know, I'm going through a pretty difficult divorce right now too.

"But I have known this lady for quite a while and we just enjoy each other's company. When we get together, we speak about stuff like the environment and (US politician-turned-activist) Al Gore."

A spokesperson for the star also denied the allegations of a romance, saying: "There is no relationship (between the pair) beyond friendship."