Sir Paul McCartney's North-East fiance Heather Mills has denied she is a gold digger, saying the star's fortune would only have been appealing if he was much richer.

The 33-year-old former model, who was born in Washington, Wearside, rejected suggestions made about her intentions towards the ex-Beatle, who is worth an estimated £700m.

"He knows and I know why I'm with him," she told Michael Buerk on Radio 4's The Choice. "If I was going to go out with anybody for their money, it would be with someone a lot richer."

Challenged that few people were wealthier than Sir Paul, she said: "There are a lot of people - believe me."

She added. "There are more reasons not to be with him, but he's just a great guy."

In a rare interview, she told how Sir Paul had "chased" her for months.

"He got hold of my number and eventually he said he wanted to help with my charity work. Or so he said."

She also described how her life changed dramatically when she lost a leg after being hit by a police motorbike eight years ago.

"Literally, out of nowhere, the motorbike came, chopped my leg off, threw me in the air, crushed my pelvis, punctured my lung and split my head open.

"Motorists were driving around my leg, which was lying in the middle of the street with my new trainer on - I wasn't very pleased about that."

Mills was pronounced dead four times, but somehow survived the accident.

She decided against suing the police for compensation, which she said would have made her depressed, and instead vowed to "sort myself out and help other people".

She now runs the Heather Mills Trust, a charity that provides prosthetic limbs for landmine victims.