Princess Diana's previously lost jumper is expected to fetch up to £70,000 at auction.

Princess Diana first wearing the jumper at a polo match in 1983

Princess Diana first wearing the jumper at a polo match in 1983

The red wool jumper with black and white sheep will go on sale at Sotheby’s in New York on September 7.

Sotheby’s global head of fashion and accessories Cynthia Houlton said: “This exceptional garment, meticulously preserved, carries the whispers of Princess Diana’s grace, charm, and her keen eye for fashion.”

The piece, which had gone missing for years, was first worn by the late ex-wife of the now-King Charles at a polo tournament in 1981 when he was Prince of Wales.

It's by the label Warm and Wonderful, and due to Diana's leverage over fashion, the then-new brand was overwhelmed with demand after she was seen in the jumper.

They said: “Much to our amazement, the first we knew of Lady Diana Spencer wearing the sweater was when we saw her on the front page of one of the Sunday newspapers.

“Her influence was impactful almost immediately thereafter, leading to a surge in sales and public awareness of our small label, for which we will be forever grateful.”

The jumper was sent back to the label for repairs upon the request of Buckingham Palace and they sent a new one.

The original got lost and was found gathering dust in the attic.

The jumper was discontinued in 1994, but a new version was released in 2020 in collaboration with Rowing Blazer.

Emma Corrin, who played Diana in 'The Crown' in season four, wore a replica.

The auction house famously sold Diana’s Attallah Cross to reality star Kim Kardashian for £163,800.