A suspect who carried a $20,000 Salvador Dali painting out of a San Francisco art gallery while it was open and the director was present is being sought by police.

The painting, titled "Surrealistic Bullfight: Burning Giraffe," was stolen Sunday from Dennis Rae Fine Art, the gallery's co-owner David Schach told NBC News on Tuesday. It is worth an estimated $20,000, Schach said.

According to the San Francisco Police Department, the piece was taken sometime between 4:40 p.m. and 5:45 p.m.

Security footage showed a man carrying a large frame on Geary Boulevard toward Union Square, Schach said.

The gallery does not lock up its art, so the suspect just grabbed it off the wall, Schach said.

"It happened quickly," he said. "The gallery director was speaking with other customers at the time of the theft."