A rare painting of an aquamarine-blue lake in British Columbia by Winston Churchill has sold at auction for nearly $87,000.

That sale greatly surpasses the estimated price of $11,000 to $14,000. The piece was sold for £47,500, or $86,936 CAD, by Sotheby’s at an auction in London.

Churchill painted the piece during a summer vacation through the Rocky Mountains in 1929, before he became Britain's prime minister. He was known for his love of vast skies and dramatic landscapes, and he captured the vista at Emerald Lake, B.C. with a palette of oil paints.

Churchill eventually gave the painting to his long-time bodyguard, Sgt. Edmund Murray, whose children later inherited the piece. Murray’s family decided that, after years in their private collection, it was time to sell.

Murray’s son, Bill Murray, told The Canadian Press that his family is delighted by the higher-than-expected sale, but not surprised.

"Even in its damaged state, it is a wonderful painting and the link with Sir Winston's visit to your area in 1929, is just about unique," Murray said in an email.

"Having read all the pre-sale reports in the Canadian media, I am not really surprised that this great painting attained such a high figure. Churchill paintings are much sought-after.”

Murray added: "Had it not been damaged, it would have fetched a much higher price and perhaps ended up in a private collection in Russia or China, never to be seen again."

For years, the painting was mistakenly believed to be of nearby Lake Louise in Alberta. At some point Churchill wrote “Lake Louise, Canada” on the corner of the canvas.

However, Canadian historian David Finch noticed that the scene resembled Emerald Lake more than Lake Louise, and reached out to Murray’s family to correct the record.

Murray’s family has said they hoped the painting would be sold to a Canadian collector, but it’s unclear who bought the artwork. Sotheby’s is notoriously tight-lipped about its buyers.

Regardless, Murray has his suspicions.

"I am pretty sure that it will go to Canada, although Sotheby's are very discreet when it comes to letting out information about the buyer, even to the seller," he said.

With files from The Canadian Press