Toronto police are looking for a woman accused of stealing a rock with an inscription from Japanese artist Yoko Ono that was valued at US$17,500.

Police allege that last month, a woman entered the Gardiner Museum in Toronto and stole the rock.

Police spokesman Gary Long says the theft was possible because Ono designed the exhibit as an interactive piece.

The rock was one of many that were laid out to resemble a riverbed in the exhibit.

Each of the rocks features an inscription from Ono, and the stolen rock had "love yourself" written on it.

"People can actually go up and interact with it, pick up the rock, say a prayer, meditate, that sort of thing, and then put the rock back," Long says, adding that it's unusual to deal with thefts from museums because exhibits generally aren't interactive and have barriers protecting them.

"I guess this is something that Yoko Ono believes in, the interactive part of it," he says. "So it's an unusual circumstance."

The suspect has been described as 55-60 years of age, 5-foot-4, wearing a black coat, a red scarf with black stripes, black pants, a black hat and black shoes.

Police are asking anyone with more information about the theft to reach out.