Not many used workout garments would reach a pretty penny at auction but, then again, a navy cotton sweater that sold for more than $50,000 last week was no ordinary piece of clothing. A Virgin Atlantic sweatshirt previously owned by Diana, Princess of Wales, reached $53,532 at a sale held by RR Auctions in the US on Thursday. The long-sleeved design, which sports the airline's former 'flying lady' logo, was auctioned by personal trainer Jenni Rivett, who used to work with the late royal. Princess Diana was snapped wearing the sweatshirt on numerous occasions in 1995 as she dashed to and from visits to her London gym. According to Rivett, the royal wore the garment repeatedly in a bid to outsmart the British paparazzi, ensuring images taken on multiple occasions looked almost identical and were therefore less valuable. "It became her most worn top on her regular visits to the gym," said the personal trainer in a statement. "She felt there were far more important issues to focus on in the world than her gym attire and therefore decided that wearing the famous Virgin sweatshirt to every session would be a good way to stop the media frenzy." Rivett added that the sweater was personally gifted to Princess Diana by Sir Richard Branson, founder of Virgin. The baggy cotton-polyester jumper was expected to sell for around $5,000, according to RR Auctions' previous estimates, and was snapped up by a bidder who wished to remain anonymous. Rivett had previously said she would use the proceeds of the auction to financially support a family in Malawi. The sale comes just weeks after several other items of Princess Diana's wardrobe went under the hammer in London. In an auction held last month, three outfits made a combined total of £262,500 (Dh1.2 million), including one worn by the royal during an official visit to Bahrain with Prince Charles in 1986. The nautical-inspired navy and white striped look by David and Elizabeth Emanuel, the duo behind Princess Diana's 1981 wedding gown, sold for £120,000.