The Globe and Mail, citing sources, said Doak, 59, was found dead Thursday morning in a hotel room.
Doak was chairman of Toronto-based uranium exploration and development company Khan Resources (TSX:KRI),
The public relations officer for the Police Authority of Mongolia confirms the death of an unidentified Canadian man on the 16th floor of the Blue Sky hotel in Ulan Bator.
The officer said a preliminary autopsy found there was no foul play but added that a final autopsy report would be available in four days.
The federal government confirmed that a Canadian has died in Mongolia, but would not provide details. A Foreign Affairs spokesman said consular officials were in contact with authorities to gather more information.
The president of Khan Resources did not immediately respond to an email seeking confirmation of Doak's death.
Khan Resources website says the company was involved in the development of the Dornod uranium property in Mongolia and became embroiled in a dispute with the Mongolian government over the mining rights.
The Globe reported that Doak started out as an analyst and later made a name for himself as a critic of Canada's corporate elite who was unafraid to put chief executive officers on the spot.
In addition to his role with Khan, Doak was also president of L'Alliance Francaise de Toronto and was president and managing director of Megantic Asset Management Inc. from 2002 until last year.
Previously he founded Enterprise Capital Management Inc. where he served as the president and managing partner from 1997 to 2002 and had also served as a vice-president of ScotiaMcLeod Inc., and of First Marathon Securities Ltd. and had more than 25 years of experience as an economist and chartered financial analyst.
— With files from The Associated Press