A slice of cake from Prince Charles and Princess Diana's 1981 wedding has sold at a US auction for $1375 (about £833).

The cake, in its original white and silver presentation box, came with a card stating: "With best wishes from Their Royal Highnesses, the Prince & Princess of Wales."

Nate D Sanders Auctions spokesman Sam Heller said the buyer was a private collector. He said there was a small but dedicated group of royal cake collectors, including some who have bought cakes dating back to the reign of Queen Victoria, who married in 1840.