A new world record has been set the sale a postage stamp. Not just any old stamp, but a one-of-a-kind. The 1856 British Guiana One-Cent Magenta was sold an auction New York $9.48 million. The auction house, Sotheby's, said it was the fourth time the stamp has broken the record. Sotheby's vice chairman David Redden said the record would never be broken again, unless the same stamp came for auction again. He told reporters: "That price will be hard to beat, and likely won't be exceeded unless the British Guiana itself comes up sale again the future." David Beech, a former curator stamps the British Library, compared the sale to buying the artwork the 'Mona Lisa'. The stamp was bought an anonymous buyer. It was previously owned John E. du Pont, an heir the du Pont chemical fortune. He is currently prison fatally shooting an Olympic champion wrestler. It was first discovered in 1873 a 12-year-old stamp collector. He sold it a few years later six shillings - about $50 in today's money and a tidy sum then. It has since had a dozen owners, including the French government. Mr Redden marvelled how sought the stamp has become. He said: "This is the most valuable item in the world weight. It's just a tiny piece of paper." He added he was happy that the stamp had been bought a collector who would cherish it, and not by an investor.