The navy Virgin Atlantic jumper was gifted to her by Sir Richard Branson in the late 1990s and she would repeatedly wear the knit to the Harbour Club in Chelsea - a nifty fashion trick to prevent the paparazzi getting new photographs of her.
The now-famous sweatshirt is emblazoned with the airline’s retro Flying Lady' logo which was first inspired by Peruvian painter Alberto Vargas’ sketches of pin-up girls in the 1930s.
Just a matter of months before the royal's tragic death in 1997, Diana gave the oversized jumper to her personal trainer and longtime friend, Jenni Rivett.
The mother-of-two wrote a touching note alongside the present which read: "Dearest Jenni, lots of love from, Diana, x".
“This sweatshirt was given to HRH by Sir Richard Branson. It became her most worn top on her regular visits to the gym,” Rivett said in the garment’s auction notes.
“She felt there were far more important issues to focus on in the world then 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.”
An anonymous bidder took home the iconic jumper and in a recent Facebook post, Rivett explained that she would donate the money to a family in Malawi in tribute to Princess Diana.
“Yes, I decided after 20 years to part with this iconic sweatshirt given to me by Priness Diana,” she explained. “It deserved a better home as it was gathering dust in my wardrobe. I'm donating the proceeds to a family in Malawi. Nothing more, nothing less. I know Princess Diana would support my decision.”