A red jumper adorned with a flock of sheep worn by the young Princess Diana has sold at auction for $US1.1 million ($A1.7 million), many times its presale estimate and a record for an item owned by the late royal.
The playfully patterned wool jumper featuring a single black sheep in a grid of white ones was bought by an unidentified bidder at Sotheby's online Fashion Icons sale.
The auction house had valued it at between $US50,000 ($A77,288) and $US80,000 ($A123,661) ahead of two weeks of bidding that ended on Thursday.
With 15 minutes left until the sale closed, the highest offer stood at $US190,000 ($A294,000) but leapt to $US1.1 million after a final flurry of bids.
The previous record for a piece of Diana memorabilia was $US604,800 ($A934,877) for a Victor Edelstein-designed ballgown sold by Sotheby's in January.
The sale also smashed the existing auction record for a sweater, the $US334,000 ($A516,285) paid in 2019 for Kurt Cobain's green cardigan from Nirvana's MTV Unplugged concert.
The 19-year-old Lady Diana Spencer was photographed in the eye-catching ovine garment at a polo match in June 1981, soon after her engagement to Prince Charles, who was then heir to the British throne.
Diana was already becoming a style icon - and one of the world's most photographed women - and the moment gave a big boost to designers Sally Muir and Joanna Osborne, who made the sweater for their small knitwear label Warm & Wonderful.
A few weeks later, Muir and Osborne received an official letter from Buckingham Palace explaining that Diana had damaged the sweater and asking whether it could be repaired or replaced.
The original was returned, showing damage to a sleeve the designers thought might have been caused by snagging on Diana's diamond and sapphire engagement ring.
A new sweater was knitted and dispatched, and Diana was photographed wearing it with white jeans and a black ribbon tie at an event in 1983.
Osborne discovered the original lying forgotten in a box in an attic earlier this year.
Diana, the mother of Prince William and Prince Harry, divorced Charles in 1996.
She was killed in a car crash in Paris in 1997 at the age of 36.
Some have speculated that the princess liked the "black sheep" pattern because she felt like an outsider in the royal family.
Emma Corrin sported a replica as the young Diana in season four of The Crown.
Muir and Osborne, who still sell a version of the design, said that "while we are forever indebted to (Diana) for the impact this had on our business, our deepest appreciation lies in the knowledge that she shared a unique connection to the black sheep design".
"We are thrilled that this cherished sweater has now found a new home, carrying with it the enduring legacy of Princess Diana," the designers said in a statement.
Australian Associated Press
