MILWAUKEE (AP) — An original Pablo Picasso print worth up to an estimated $50,000 was stolen from a downtown Milwaukee art gallery.

WITI-TV reports appraiser Bill DeLind says his business partner noticed the original 1949 print was missing from DeLind Fine Art Appraisals on Friday. Picasso only did 30 of the prints and signed each with a green crayon in the lower right corner.

DeLind says someone could have walked in the unlocked door unnoticed because he and his business partner were upstairs. The gallery does not have surveillance cameras. He says he hopes a camera across the street captured the thief.

Delind says he called police and then nearby art appraisers, museums and art galleries around the country, in case the print turns up.

Milwaukee police confirm a report was filed for the stolen painting.