MARINA DEL RAY (CBS) – Sheriff’s detectives are questioning the authenticity of what was thought to be a Rembrandt drawing after it was stolen from an art ext exhibit in Marina Del Ray two weeks ago.

“Right now as of today, we cannot verify that in fact this is a Rembrandt,” Steve Whitmore of the LA County Sheriff’s Dept. said.

The lithograph which was presented as an original, signed, Rembrandt piece was stolen from the Ritz Carlton on Aug. 13. It mysteriously reappeared in St. Nicholas Episcopal Church in Encino on August 16 after reportedly being left there by the thief.

Sheriff’s detectives immediately began searching for the thief and prepared to release still photos taken by surveillance cameras at the hotel during the theft.

Investigators decided to hold the photos after learning art experts around the world had never heard of the drawing called, “The Judgment.”

“We’ve gone all over the world. We have spoken to many, many people. We cannot find this documented anywhere. It is possible that it is an undocumented Rembrandt; one of those rare commodities. Possible but unlikely.” Whitmore said.

Detectives are now shifting the focus of their investigation away from the alleged thief to the authenticity of the artwork.