A Dartmouth sandwich shop is looking for a thief who grabbed a celebrated piece of art off their wall and strolled out of the café and into the afternoon sunlight.

Renee Lavallee, owner of the Canteen on Ochterloney Street, said just before a busy lunch hour started on Monday, a man sat down at the counter and looked around "like he was assessing the place."

It soon got busy with the lunch rush. She says that's when he pulled the painting off the wall and strolled out the front door. Nobody noticed at the time, but Lavallee did see the gap on the wall when she started work today.

To the older gentleman who came in during a busy lunch rush, took a painting off our wall & walked out with it. Wtf??? Please return it —@TheCanteenNS

This happened yesterday. We're pretty bummed about the whole incident. If you any further info please contact us. Thanks for the love! 🙏 <a href="https://t.co/lsXIutQCP0">pic.twitter.com/lsXIutQCP0</a> —@TheCanteenNS

"We looked at our security camera and noticed that he'd come right in the middle of lunch time," she told CBC News Tuesday. She says the footage shows the man taking the painting.

"We've been open for almost three years and this is the first time anything has been stolen," she said. "There's no point in us going [to police] because I don't think there's anything they can really do about it."

The piece was one of the original paintings of the Dartmouth ferry done by Eric Miller, an artist and clothing designer. The café had one of his limited run.

"As a business owner and a human being, it breaks my heart to know that there are people who would just come in and take something," Lavallee said.

Eric Miller's Take a Ride to the Darkside went missing from the Canteen. (Dartmouthclothing.ca)

She hopes another diner saw the man and perhaps recognized him, or that someone noticed a brand-new painting in someone's house. "Maybe they could point us in the right direction."

If the art thief does feel the sting of his conscience, she says he should bring it back. "They can just drop it off at our order counter and then walk away."

Const. Dianne Woodworth of Halifax Regional Police urged the café to contact them so they can start an investigation.

"The video would be distributed to police members to see if anyone knows the suspect, and potentially would be put out to the public," she said.