When the list of suspects is drawn up, there will be no shortage of names.
A sketch by Salvador Dali, the Spanish master of Surrealism,worth at least $500,000 (£315,000) has been stolen from under the noses of prison guards on Rikers Island in New York.
Dali drew it in 1965 for Anna Moscowitz Kross, a Correction Department commissioner, as an apology after he was forced to cancel a visit intended to support a programme for art in prison.
The sketch of Jesus on the cross was kept in a locked display case at the jail for years, first in the dining room and later in the lobby. But workers realised on Saturday that it had been replaced by a copy. Tom Antenen, a Correction Department spokesman, said: "It is something that they see every day and something didn't look right about it yesterday."
An appraisal in the 1980s concluded the work was worth at least $175,000, but, more recently, experts suggested the value was at least three times that figure.
Dali, who died in 1989, sent a message to the artists of Rikers Island with his drawing. "You are artists. Don't think of your life as finished for you. With art, you have always to feel free," he wrote.