A 19th CENTURY postage stamp from British Guiana is set to fetch a record price when it goes on sale in New York this month, the auction house has said.The 1856 one-cent Magenta, regarded by collectors as the world’s most famous rare stamp, might sell for up to US$20m (£12m/15m euros), Sotheby’s says.

The unique stamp has set a world record each of the three times it has been sold at auction. The current record for a single stamp sold at auction is US$2.3m.
The Swedish Treskilling Yellow was last officially sold in Zurich in 1996 for 2.88m Swiss francs (about US$2.3m at the time).
It is believed to have set another world record in May 2010 but its buyers did not disclose how much they paid.

‘Colourful history’
The British Guiana one-cent Magenta is the sole surviving example of its kind and regarded as the most well-known of rare stamps.
“This is just incredible because it has always been a rarity,” Richard Ashton, Sotheby’s stamp specialist, told the BBC.
“It is something that every schoolchild who was a stamp collector, everyone knew this was the rarest stamp – it has always had this mystique about it.”
The British Guiana one-cent Magenta was last bought in 1980 by John du Pont, a chemical industry millionaire, who kept it largely out of public view, locked away in a vault.
Du Pont was jailed for shooting dead an Olympic gold medal-winning wrestler in 1996 and died in 2010. The stamp is being sold as part of his estate.
Printed in black on magenta paper, the British Guiana stamp bears the image of a three-masted ship and the Latin motto “we give and expect in return”.
It was produced in Georgetown, British Guiana (now Guyana) after a shipment of stamps was delayed from London, threatening to disrupt the postal service. It carries a post mark, showing it has been used, and is initialled by a post office employee.
Its first owner was a 12-year-old Scottish boy who apparently found it among family papers in 1873.
“Since it was discovered, it has had this wonderfully colourful history and that certainly adds to its appeal,” said Mr Ashton.
The stamp has not been on view publicly since 1986, when it was exhibited at the Ameripex 1986 International Stamp Show in Chicago, Sotheby’s said.
It will travel to cities, including London and Hong Kong, before returning to New York where it will go on sale at auction on June 17.