Prince Andrew has revealed he stayed friends with Sarah Ferguson after their divorce "more for family than anything else."

The Queen's youngest son spoke candidly of his ongoing relationship with his ex-wife, in an interview with US network CNBC.

The couple were married in 1986 with all the pomp and ceremony of a royal wedding, but separated in 1992 and divorced four years later.

The marriage was plagued by scandal after Ferguson was photographed on holiday with American millionaire Steve Wyatt and later caught in a compromising situation with her financial advisor John Bryan.

She was targeted by the press for her battle with her weight and was implicated in a cash for royal access controversy. A British tabloid had captured her on video offering a stranger access to Prince Andrew in exchange for $40,000 in on-the-spot cash.

Dubbed an embarrassment to the palace, Ferguson has reportedly been ousted from the royal camp by the Queen, but the couple, who have two daughters, Princesses Beatrice, 26, and Eugenie, 24, together, have maintained a close friendship, with Ferguson describing Andrew as "her rock" through turbulent times.

In the interview, to be broadcast in America this week, the 54-year-old royal said of their relationship: "It's just part of life's rich tapestry if you have been married to somebody. I just see it as illogical not to be a friend at the end of the day, regardless of what your circumstances are."

The Duke and Duchess of York have been public about their amicable split and describe themselves as "the world's happiest unmarried couple."

While the Duchess, 54, was noticeably absent from Prince William and Kate Middleton's wedding, she continues to live at the Duke of York's home in Windsor, and even visited the Queen's estate in Balmoral, Scotland for a break earlier this summer.

It's believed Prince Andrew conducted the TV interview as an image building exercise after his acquaintance with convicted American paedophile Jeffrey Epstein became public.

Commenting on the scandal, the Prince said that he accepted he had to "live with the rough and live with the smooth in a 'free world, with freedom of speech."

He also used the interview to promote his iDEA scheme, which aims to improve young people's computer and digital skills to help them get a job.

Talking about the scheme Andrew said: "I believe that the next generation are as capable and have greater opportunities than our generation ever had. So it's about making those possibilities more relevant and more alive to young people today."