The Red Deer Advocate reported late Thursday that Keegstra died June 2.
In 1981, Keegstra was warned by a district school superintendent to stop teaching Jewish conspiracy theory as if it were fact.
But Keegstra was fired the following year, and in 1984, was charged with wilfully promoting hatred against an identifiable group.
Keegstra was convicted in 1985, but the Alberta Court of Appeal overturned the conviction until it was restored by the Supreme Court of Canada in late 1990.
That set the stage for a retrial, and in 1992, a jury convicted Keegstra and he was fined $3,000.
Keegstra had told students in Eckville that the Holocaust was a fraud and described Jews as treacherous and evil.
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