Was Canadian painter Tom Thomson the victim of a murder plot, a fistfight, or an unfortunate accident when he died suddenly while fishing on a northern Ontario lake nearly 100 years ago?

That’s been the question that has haunted art lovers and mystery enthusiasts for years.

And now, a new book by York University adjunct professor Gregory Klages, "The Many Deaths of Tom Thomson," promises to offer the clearest picture yet about what happened that day in July, 1917, when the painter was last seen alive.

As many Canadians know, Thomson went missing while on a fishing trip on Canoe Lake, in Ontario’s Algonquin Park. His empty canoe was found later that day, but it would take another eight days before his body was finally found, floating on the lake.

A coroner quickly determined that Thomson had drowned and his body was buried, then exhumed and re-buried again closer to home.

At the time, Thomson was little known among Canadians, but nearly two decades later, biographer Blodwen Davies caused a small stir when she published a book suggesting Thomson’s death had been more than an accident.

“She interviewed a park ranger who had been there when Thomson’s body was discovered and he suggested to her the theory of accidental death wasn’t right,” Klages told CTVNews.ca.

“This spurred conjecture that has never stopped since.”

Some of that conjecture has included assertions that Thomson had been the victim of murder, either by gunshot, the edge of a canoe paddle, or a drunken barroom fight the night before. Others said he had died of suicide, despondent about a lover who was pregnant with his child.

All these theories actually helped to forge the Tom Thomson mythology, says Klages, making the now-beloved painter just as famous for his mysterious death as for his groundbreaking art and lingering influence on the Group of Seven.

“It’s part of what was used to build him up as fascinating and influential person in Canadian history,” Klages said.

Thomson’s death intrigued the public right from the start, coming during the First World War at a time when manly ruggedness was celebrated and the dangerous wilds of northern Canada fascinated.

“His death was important to building his reputation and building this Canadian school of masculine toughness,” Klages said.

Klages’ own interest in Thomson’s death began more than 10 years ago, when he helped create a website devoted to Thomson called Death on a Painted Lake as part of the Great Unsolved Mysteries of Canadian History project.

That led to a longer essay and finally this new work, released almost 100 years after the landscape painter’s death.

In researching the book, Klages was able to look at witness statements and new archived documents that became available only in the last 15 years or so, which Klages notes is a rare thing among researchers of a mystery as old and well-known as this one.

The result is a book that he says will appeal to anyone who loves a good “whodunit” tale.

“There’s this trope that Canadian history is boring. Well, I hope this book shows that our history certainly is anything but boring. There’s intrigue and mystery,” Klages said.

“I think that, even if people aren’t interested in Canadian art, if you’re interested in history, or true crime, or Algonquin Park, this story really has everything.”