A mountainscape painting by Group of Seven founder Lawren Harris has become the most expensive artwork ever to sell at a Canadian auction.

Mountain Forms, a renowned 1926 painting of Alberta's Mount Ishbel in the Sawback Range of the Rocky Mountains in Banff National Park, sold for $9.5 million at the Heffel Fine Art Auction House in Toronto Wednesday night.

Including the 18 per cent buyer's premium, which comes out of the winning bidder's pocket and goes to the auction house, the total price was $11.21 million.

"It deserves to be the record Canadian artwork at auction worldwide," auction house president David Heffel told CBC News shortly after the sale.

"It was a great moment for Canadian art, for Canadians and for Lawren Harris."

The buyer behind the winning bid, which came from inside the room, remains anonymous.

On Nov. 23, 2016, the Lawren Harris canvas Mountain Forms was sold by Heffel Fine Art Auction House for a hammer price of $9.5 million. The overall price, with commission, was $11.21 million, more than double the previous record-holder. 2:15

The 1.5-metre tall, 1.8-metre wide canvas vastly surpassed its expected sale price of between $3 million and $5 million. It replaces Paul Kane's Scene in the Northwest as the record holder. That painting was purchased in 2002 by art lover and media baron Ken Thomson for a total of $5,062,000.

Lawren Harris' Mountain Forms fetches 9.5 million (hammer price) , breaks record at <a href="https://twitter.com/hashtag/heffelauction?src=hash">#heffelauction</a> <a href="https://twitter.com/hashtag/cbcent?src=hash">#cbcent</a> <a href="https://t.co/epMcax9Yh0">pic.twitter.com/epMcax9Yh0</a> —@deanasumanac

Mountain Forms hails from the collection of Imperial Oil, which has reduced its art holdings in recent years. As part of a streamlining of its corporate collection, the company has donated works to Canadian galleries and given proceeds from some art auctions to the United Way and its partners.

It was most recently on loan to The Idea of North: The Paintings of Lawren Harris, an exhibition co-curated by comedian and art lover Steve Martin.

Pulling together some of Harris's best known works from top museums, galleries and private collections across Canada, the show debuted at the Hammer Museum in Los Angeles before travelling to the Boston Museum of Fine Arts and the Art Gallery of Ontario in Toronto.

There is a growing international interest in Canadian art, British art historian Ian Dejardin said earlier this week. He has co-curated several successful and high-profile exhibitions of Canadian art in London in recent years.

Harris, in particular, "is such a powerful and attractive artist. He is someone who is ripe for appreciation abroad, particularly in the States, where they have the comparison with someone like Georgia O'Keeffe" — an "international superstar" whose work recently packed crowds into the Tate Modern, he told CBC News.

"Lawren Harris deserves to be seen in the same breath, I think, as that."

Over his career, Harris himself was a champion of Canadian artists, Heffel noted, so it is fitting that one of his works is now the record-holder.

And about that anonymous buyer?

"I feel optimistic that the work won't be hidden in a back, private closet somewhere. I'm optimistic that we'll live another day to see Mountain Forms," he said.

A mountainscape painting by the Group of Seven founder has become the most expensive artwork ever to sell at a Canadian auction, Deana Sumanac-Johnson reports 2:38

Additional Harris works fetched lofty prices during the auction as well, including Mountain Sketch LXIII ($2 million) and Mount Robson from Berg Lake ($1.888 million).

The evening also saw records set for artists ranging from A.J. Casson (Country Crisis, $1.534 million) to Takao Tanabe (Inside Passage 2/87: Grenville Channel, $188,800). Notable highlights included: