A painting by a Norwegian man who pasted bills equivalent to $16,300 to the canvas was stolen from the gallery where it was displayed over the weekend, Oslo's MGM Gallery said Monday. The robbers broke into the gallery overnight Saturday by smashing a window and cut all the cash out of the canvas.

After they left only the frame that formerly housed artist Jan Christensen's 6.5-by-13-foot painting "Relative Value" remained.

Marina Gerner-Mathisen, who owns the gallery, told AFP, "Apparently they are nice because they took the canvas out of the frame."

Christensen said the exhibition was scheduled to end Monday and that Norweigian art collectors had already purchased the painting.

Norwegian news agency NTB quotes him as saying, "That was a pretty dramatic incident. We were afraid of something like this. The picture was insured and the gallery was equipped with an alarm."

Gerner-Mathisen said the theft is under investigation.