I'll help raise Kate and William's baby, says uncle with a drug past

The Duchess of Cambridge, Kate Middleton's uncle, Gary Goldsmith, has become the first member of her family to cash in on their relationship with her by granting an exclusive interview to Hello! magazine.

Goldsmith, who was filmed taking cocaine and boasting that he could arrange "deliveries" of the drug in a tabloid sting operation four years ago, said he would "of course" play a role in the upbringing of the Duchess's baby, the future monarch, when he or she is born in the summer.

He also claimed credit for helping the Duchess to be reuntied with the Duke of Cambridge after their temporary break-up in 2007, saying she stayed at his villa on Ibiza where she spent "a huge amount of time on the phone, walking around the pool".

Goldsmith's decision to speak to Hello! will be a further embarrassment to the Middletons and the Royal family, who forgave his previous indiscretions to allow him to attend the royal wedding in 2011.

Hello! said it never discusses its financial arrangements with interview subjects, but the magazine has paid more than 1 million pounds for some previous exclusives, such as access to celebrity weddings. Asked whether he was paid for the interview, and if so how much, a spokesperson for Goldsmith said, "We would never reveal anything like that with any client."

Sources close to Goldsmith said he had been keen to "set the record straight" about his drug-taking, but the majority of the interview is given over to his relationship with the Duchess.

On the subject of her baby, which is due in July, he says, "Would I play a part in the future monarch's upbringing? Of course I would. And it's another young baby growing up to play with, which I'd love to be a part of."

He said the Duchess visited his 6 million pounds villa, La Maison De Bang Bang, "to get away from everything" in 2007 following her split from her future husband.

"Kate was very low," he said, "spending a huge amount of time on the phone, walking around the pool. It's a very relaxing place and it has a very nice vibe and you can hear the sea at night. So in some small way I just hope that being there helped."

In August 2006, the Middleton family stayed at the villa with Prince William, who enjoyed taking mud baths at a neighbouring island.

Goldsmith recalled, "Back at the house a friend of mine was teaching William how to mix on the DJ decks and he performed to the whole family as they swam. So they all had the Ibiza experience - from mud baths, to [the nightclub] Pacha, to learning how to mix music." He said he met the Prince when he was invited to the Middletons' Berkshire home as a thank-you for the loan of his villa.

"There was Kate in the kitchen cooking supper and William was making tea for everybody," he said. "I was a cheeky chap, asking him if he was the one who had broken four glass [ornamental] pyramids at my house by throwing a ball around. We just laughed out loud, much to my sister's dismay." A spokesperson for the Duchess declined to comment.