A bookseller has been convicted of stealing a rare edition of a Harry Potter book worth £1,675 by swapping it with a novel of "very little value".
Rudolf Schonegger pocketed the copy of Harry Potter And The Goblet Of Fire, signed by JK Rowling, at Hatchards in Piccadilly, on New Year's Eve.
CCTV showed him browsing the shop before making the switch while a staff member had her back turned.
He will be sentenced on April 3 at Westminster Magistrates' Court.
During a trial at Hendon Magistrates' Court, Hatchards manager Helen Mills said it was rare to have a copy bearing the author's signature "because she doesn't sign too many."
Schonegger was arrested after booksellers, who had bought his wares in the past, recognised him from CCTV images.
As well as stealing the Harry Potter book - which is yet to be recovered - the 55-year-old sold a bound copy of The Old Man And The Sea by Ernest Hemingway, worth £700, on 21 December.
District Judge Nina Tempia found Schonegger, of Bayswater in west London, guilty of theft and two charges of handling stolen goods.
She said: "I found the defendant to be a dishonest, evasive and untruthful witness."