Catherine, Duchess of Cambridge. Picture: AP

Catherine, Duchess of Cambridge, has reportedly donated her hair to children's cancer charity the Little Princess Trust.

The 35-year-old royal is believed to have chopped off seven inches of her hair in aid of the Little Princess Trust charity, which takes hair and transforms it into wigs for young children battling cancer who have lost their hair through chemotherapy or radiotherapy treatment.

Catherine is said to have had the idea whilst her 30-year-old hairdresser Joey, who works for Richard Ward Hair in Chelsea, was cutting her tresses during a private session at Kensington Palace.

A royal source told the Daily Express newspaper: "Four months ago Joey persuaded her it was time to take off some of her hair; he said it was just getting too long. While Joey was snipping away the idea came to her of doing some good with it rather than throwing it away. 

"She mentioned it to Joey, who thought it was a brilliant idea. It was sent using someone else's name, so that the trust didn't know it was from a royal source - they just thought it was from a female donor in the Kensington area."

Although Kensington Palace has not confirmed the claims, sources insist the "heartwarming" gesture means one brave child could end up wearing a wig made from "a real princess's hair".

The source added: "It's lovely to think somewhere a little girl is happily wearing a wig made from a real princess's hair. It's a very heartwarming thing for Kate to have done, and very thoughtful to use hair that would have otherwise just been thrown away."

Catherine - who has four-year-old son Prince George, two-year-old daughter Princess Charlotte, and is expecting her third child with her husband Prince William - isn't the first high profile star to donate to the trust either.

In 2016, One Direction star Harry Styles famously uploaded a photo of his chopped off pony tail to Instagram after he made the bold move to take his long tresses back to a short crop.

Whoops. #Littleprincesstrust

A post shared by @ harrystyles on

He captioned the snap: "Whoops. #Littleprincesstrust (sic)"