Warhol self-portrait sells for $23m

A self-portrait by Andy Warhol sold for £10.8 million ($23 million) - double its pre-sale estimate - to an anonymous bidder in London yesterday.

Auctioneer Christie's says the work had been in a private collection since 1974.

It is one of a series of 11 self-portraits Warhol created.

The image of red and white silkscreen ink on canvas shows the artist with his hand to his mouth.

It was executed in 1967.