It sounds like a caper from a movie: a thief seems to have swapped out the famous portrait of a scowling Sir Winston Churchill, photographed by Yousuf Karsh in 1941, with a signed copy.

A staff member at Ottawa's Château Laurier noticed on Friday that the frame in the Reading Lounge wasn't hanging properly and didn't look the same as the others in the collection. An inspection revealed the photo in the frame was not the original, but it is not clear how long the copy has been hanging.

The hotel's general manager, Geneviève Dumas, said staff are "deeply saddened by this brazen act."

Police have been informed and the hotel is seeking information from the public about the theft.

"The hotel is incredibly proud to house this stunning Karsh collection, which was securely installed in 1998," Dumas said in a statement.

Six of the portraits are displayed in the Reading Lounge and another nine in the downtown hotel's Karsh Suite.

The remaining five photos in the lounge have been taken down until they can be secured properly.

The photographer and his wife lived at the Château Laurier for 18 years. Karsh's studio was in the hotel for 20 years, from 1972 on, and it was the location of several of his famous portraits, including one of South Africa's Nelson Mandela in 1990.

The Churchill portrait changed Karsh's life, according to the artist's website. It was taken after the then-British prime minister gave a speech to Canada's House of Commons on Dec. 30, 1941.

Churchill began by thanking Canadians for their wartime efforts, saying, "I think it is extremely unlikely that this war will end without the Canadian Army coming to close quarters with the Germans, as their fathers did at Ypres, on the Somme, or on the Vimy Ridge."

He also spoke of the collapse of the French army and the failure of the French government.

"When I warned them that Britain would fight on alone whatever they did, their generals told their prime minister and his divided cabinet, 'In three weeks England will have her neck wrung like a chicken.' Some chicken; some neck," he said.

According to Karsh, he waited in the Speaker's chamber after the "electrifying speech" to take a photograph, but Churchill "growled" that he hadn't been informed. Karsh recalled that the prime minister refused to put down his cigar — and it's what happened next that allowed him to immortalize the scowl.

"Then I stepped toward him and, without premeditation, but ever so respectfully, I said, ‘Forgive me, sir,’ and plucked the cigar out of his mouth," Karsh recalled, according to a write-up on the Estate of Yousuf Karsh website.

"By the time I got back to my camera, he looked so belligerent he could have devoured me. It was at that instant that I took the photograph."

The portrait was added to the British five-pound note in 2016, 14 years after Karsh's death.

This report by The Canadian Press was first published Aug. 22, 2022.