But two men made off with it in the early hours after flinging a brick through the window of the Saint Giles Street Gallery.
The gallery manager, who asked not to be named, found a brick among the debris and said: “What’s astonishing to me is that it’s a quiet listed building in a conservation area. They just smashed the glass.
“I don’t think it was stolen for value. I think someone just wanted the picture. They would not necessary have known how much it was worth – there was no price tag.
“I phoned Chris Smith this morning to let him know and he said he was rather flattered.
“I can’t believe that someone was that desperate for it. It makes me feel that someone has that desperation to actually smash a glass window at coming up to 3am and break into a shop and steal it is a very sad state of affairs.”
Police said an early witness report said two men had been spotted carrying a “large painting”.
The manager said the gallery, which has been open for a decade, had occasionally suffered from walk-in thefts of photographs, but had never been broken into before.
He said that, ironically, the gallery had no such problems when it offered what it claimed was the world’s most expensive piece of Beatles memorabilia for sale at $11m in 2009.
The rare album cover, which showed The Beatles dressed in butcher outfits and surrounded by body parts from dolls, was exhibited behind bullet-proof glass and included a hand-written note from John Lennon telling a friend he could sell it for $11m.
The manager said the previous items stolen were photographs of a sea-scape and a dog urinating.
The raid happened at about 2.30am on Monday morning, and neighbours who heard the glass smash called the police.
Police asked anyone with information to contact PC Hollie Fisher at the Bethel Street Station on 101.