A 1936 Canadian Dot Cent, made by the Royal Canadian Mint in 1937, sold at auction for $402,500 US. (Canadian Press)

A rare Canadian penny billed as "the king of Canadian coins" was purchased for $402,500 US at a New York auction Sunday.

The famed 1936 Canadian "Dot Cent" was the highlight of a group of coins billed as the single most substantial collection of Canadian coins ever offered at public auction.

Heritage Auction, which ran the sale, had predicted the penny would fetch at least $300,000.

A blogger at antiques.com predicted the sale would "change the face of the Canadian numismatic market as a host of coins that have not seen the open market in years make their way back into the general coin collecting populace."

Only three Canadian Dot Cents were ever made. (Canadian Press)

The penny is rare because it's one of only three known 1936-dated Canadian cents struck by the Royal Canadian Mint with a small but distinctive dot below the date to indicate it actually was made in 1937.

The penny bears the image of King George V, who died in January 1936 but coins with his image continued to be made that year.

When George's successor, Edward VIII, abdicated the throne in December of the same year, the coin-making dies prepared for 1937 with Edward's image were no longer valid.

The mint experimented with 1936-dated coins struck in 1937 with a dot added to the design to distinguish them from coins struck earlier.

Dot Cents were long considered unavailable as all three were held by noted American numismatist John Jay Pittman, who paid $250 for them in 1954.

They were auctioned off after his death in 1996.

With files from The Canadian Press