A painting originally valued at a few hundred pounds before being attributed to Spanish master Diego Velazquez fetched three million pounds ($4.7 million) at a London auction on Wednesday.
The hammer price was at the top end of pre-sale estimates set by Bonhams auctioneers, who discovered the portrait of an unknown gentleman among a collection of paintings believed to have been by British 19th century artist Matthew Shepperson.
The works were consigned for sale at Bonhams in Oxford, but experts suspected the portrait was by a different artist and sent it to the old masters department in London for further analysis.
Consultant Brian Koetser had his suspicions confirmed by Peter Cherry, lecturer at the History of Art department at Trinity College Dublin who Bonhams called "one of the world's foremost authorities on Velazquez and his school."
After studying the painting, including with x-ray technology, Cherry decided it was by 17th century Spanish artist Diego Velazquez and dated from 1631-1634 when he was in Italy or shortly after he returned to Spain.
Bonhams said "many experts" were consulted in order to confirm the attribution to Velazquez.
It is one of only around 100 works by the painter known to exist, of which a handful remain in private hands.
Andrew McKenzie, director of old master paintings at Bonhams, said his involvement in the discovery and sale was a highlight of his career.
A spokesman said the work, featuring a balding man in black tunic and white "golilla" collar, had gone to a U.S. buyer.
OTHER OLD MASTERS
The other highlight of the Bonhams sale was "Three Peaches on a Stone Ledge With a Painted Lady Butterfly" by Dutch artist Adriaen Coorte, which fetched 2.1 million pounds, an auction record for the artist and well above estimates of 300-500,000 pounds. Overall the auction raised 6.3 million pounds ($9.9 million)
More records tumbled at Christie's late on Tuesday, where "The Battle between Carnival and Lent" by Pieter Brueghel II sold for 6.9 million pounds and Willem van de Velde II's "Dutch men-o'-war and other shipping in a calm" fetched 5.9 million pounds.
But Francisco Goya's "Portrait of Don Juan Lopez de Robredo," estimated to be worth 4-6 million pounds and billed as the star lot on the night, failed to sell.
The old master and British paintings auction raised a total of 24.1 million pounds ($37.8 million), within expectations.
Rival Sotheby's reached 20.1 million pounds ($31.6 million) at its equivalent sale late on Wednesday, according to results posted on its website.
Both totals were less than half those realized at the equivalent auctions held in London in July.
"The Card Players in an Interior," by 17th Dutch artist Jan Steen, sold for 4.9 million pounds, at the lower end of Sotheby's estimates if the buyer's premium is taken into account but a record for the artist.
Top lot on the night was a pair of paintings by 18th century artist Johann Zoffany commissioned by British actor David Garrick which fetched 6.8 million pounds, within expectations.
(Reporting by Mike Collett-White; Editing by Bob Tourtellotte)