A very rare 19th Century postage stamp from a former British colony in South America has sold for a record $9.5m (£5.6m) at auction in New York.
It took only two minutes for the British Guiana one-cent magenta stamp to be sold to an anonymous bidder,
The stamp had been sold three times before, each time setting the auction record for a single stamp.
It measures just 1in by 1in (2.5cm by 2.5cm), and had not been publicly exhibited since 1986.
Sotheby's auction house said that apart from setting a new world record price for a stamp, it was also the most expensive item by weight and size ever sold.
"Every collecting area has its Holy Grail. For stamps it is The British Guiana," Sotheby's wrote on its website, adding the stamp is often described as the "most famous" and "most valuable" in the world.
The stamp, printed on magenta paper, bears a three-masted ship and the colony's motto, "We give and expect in return".
It initially went into circulation when a shipment of stamps was delayed from London and the colony's postmaster asked printers to make three stamps until the shipment arrived.
A one-cent magenta, four-cent magenta and four-cent blue were created, but only the one-cent stamp is believed to still exist.
The last owner of the famous stamp was John du Pont, heir to the du Pont chemical empire, who was convicted in 1997 of murdering an Olympic champion wrestler and died in prison in 2010.
The stamp was sold by his estate, with some proceeds to be donated to the Eurasian Pacific Wildlife Conservation Foundation.
It last set a record in 1980 when it was sold to du Pont for $935,000.
An 1855 Swedish stamp which sold in 1996 for $2.3m had held the previous record for a single stamp at auction.