Olympic gold medallist Peter Charles' London 2012 horse Murka's Vindicat W has been sold to the daughter of rock star Bruce Springsteen.
Jessica Springsteen, an American international showjumper, will now ride the 10-year-old gelding that secured team gold for Great Britain at Greenwich Park six weeks ago.
Britain went into a jump-off with Holland for the Olympic title and it was Hampshire-based Charles' clear round that clinched top spot.
It meant the British quartet of Charles, Nick Skelton, Ben Maher and Scott Brash gave Britain its first Olympic team showjumping gold medal since 1952.
"Vinnie is one of the best horses I have ever ridden, so the decision to move him on has not come lightly," Charles, who lives in Alton in Hampshire, said on his Facebook page.
"He produced an outstanding performance to secure team gold for Britain for the first time in 60 years, and I will never forget how that felt and how unbelievably proud he made me and my team feel.
"In order to invest in a new string of young horses in preparation for Rio 2016, we have had to make the decision to allow him to move to another rider.
"He will now be ridden by his new owner Jessica Springsteen for the USA.
"I wish Jessica the best of luck with him and I am sure he will make her proud, too."
British equestrian is braced for a period of rebuilding and consolidation following a memorable Olympics that saw home-based riders top the medal
In addition to the showjumpers, Britain's dressage trio of Charlotte Dujardin, Carl Hester and Laura Bechtolsheimer won team gold, while Dujardin also took the individual title and Bechtolsheimer
And Britain's eventing quintet of William Fox-Pitt, Mary King, Zara Phillips, Tina Cook and Nicola Wilson won silver behind pre-Olympic favourites Germany.
It is expected that Dujardin's Greenwich ride Valegro and Hester's Uthopia will be sold, while Skelton's Olympic back-up horse Carlo 273 has gone to Spanish showjumper Sergio Alvarez Moya.