An eagle-eyed hotel worker noticed something odd about a Winston Churchill portrait before discovering the original was stolen and replaced with a replica.
The portrait, taken by photographer Yousuf Karsh in 1941, has gone missing from the Château Laurier hotel in Ottawa, Canada, but for exactly how long remains a mystery.
Last week, a staff member spotted that the frame didn't match those of the other five portraits in the room, which were captured by the same photographer.
The hotel's general manager then phoned Jerry Fielder, who is the director of Karsh's estate, to determine whether it was a fake.
Mr Fielder inspected the signature and immediately noticed that it had been forged.
He told CBC on Tuesday: "I couldn't believe that anyone would do this.
"It had been there for so long and had been such a part of the hotel. It was shocking and very saddening."
Police are now investigating the theft, which they believe happened between the end of 2021 and early this year.
Mr Fielder added: "I would like [whoever took it] to give it back, but I don't think that's going to happen."
He last saw the portrait on display in July 2019, and said it was the "real thing".
In a statement, the hotel said it was "deeply saddened by the brazen act", and that it was proud of its collection of works by Karsh.
Churchill began his first term as Prime Minister in 1940, taking over from Neville Chamberlain in the middle of World War Two.
The photograph, often referred to as the 'Roaring Lion', was taken a year into Churchill's premiership, after he gave a historic speech to the Canadian Parliament.
He said: "Canada occupies a unique position in the British Empire because of its unbreakable ties with Britain and its ever-growing friendship and intimate association with the United States.
"Canada is a potent magnet, drawing together those in the new world and in the old whose fortunes are now united in a deadly struggle for life and honour against the common foe.
"The contribution of Canada to the Imperial war effort in troops, in ships, in aircraft, in food, and in finance has been magnificent."
The portrait was then taken in the chamber of the Canadian Speaker of the House of Commons.
Churchill had refused to put down his cigar so Karsh pulled it from his lips just before taking the shot, capturing him scowling.
It was hung in the hotel where Karsh previously lived for 24 years.
