Most expensive book in the world sold for $ 10 million

A rare copy of the "most expensive book in the world" surpassed pre-sale estimates to fetch more than £7 million ( $10 million) at auction in London.

Sotheby's said the price of £7,321,250, including buyer's premium, paid for John James Audubon's Birds Of America was a record for any printed book at auction.

The illustrated book by the renowned ornithologist, naturalist and painter (1785-1851), a landmark of natural history, was expected to fetch between £4 million and £6 million, The Press Association reports.

"Birds of America" is oversize - more than 3 feet tall and 2 feet wide - with 435 illustrations. When first published in 1827, the images were printed in black and white and then hand-colored by specialists.

The combination of accuracy and artistry make Audubon's work unique, Los Angeles Times informs.