World's most valuable coin fetches £4.9m at auction

The world's most valuable coin, the 1933 "double eagle" $20 gold piece, was sold for £4,859,118 at auction last night.

The coin was bought by a collector at Sotheby's in New York after becoming the only one authorised for private ownership. On top of paying a world record sum, the new owner will have to stump up a further $20 for the US Treasury after the gold coin, which has been held in Fort Knox, was issued for the first and only time.

The whereabouts of the unique but until now technically worthless coin remained a mystery from the time it was minted in 1933 until 1996 when it was seized at the Waldorf-Astoria, New York, as the respected leading British coin dealer Stephen Fenton attempted to sell it to Secret Service agents posing as dealers. The following legal proceedings resulted in a settlement which allowed the double eagle to be privately owned for the first time.

After it was struck in 1933, President Franklin Roosevelt took the US off the gold standard in an effort to help the struggling American economy emerge from the Depression. All the double eagles were ordered to be destroyed. Ten ended up in private hands but were seized or turned in during the 40s and 50s and destroyed.

David Redden, the vice-chairman of Sotheby's, said: "The story of this coin is one of the great numismatic mysteries of all time."