Monika Schaefer ran unsuccessfully for the Greens in Alberta's Yellowhead riding in 2006, 2008 and 2011, but the party rejected her as a candidate in 2015 and publicly condemned her views the next year after a video emerged.
German authorities charged Schaefer with six cases of "incitement of the people" for publishing multiple videos denying the Holocaust, said Andrea Mayer, a spokeswoman for Munich's public prosecutor's office. Schaefer's trial began July 2 and is set to continue until August 17.
"The maximum penalty for each case is up to three years' imprisonment," Mayer said.
Schaefer was visiting relatives in Germany and attended a court hearing in a different case when she was arrested on Jan. 3, and she's been in custody ever since, Mayer added.
Schaefer and her brother, Alfred, are German-Canadian and he also faces charges in Germany for Holocaust denial, said Helmut-Harry Loewen, a retired University of Winnipeg sociologist who monitors hate groups [and is a Director of the Canadian Anti-racism Education and Research Society].
"Both siblings are now emerging as key figures in the Holocaust denial movement, both in Canada and in Germany," he said. "They have supporters here in Canada."
A YouTube channel under the name Alfred S. contains several videos of the siblings questioning the existence of Nazi death camps during the Second World War.
In the 2016 video that prompted public denunciation by the Greens, Monika Schaefer calls the Holocaust the most "pernicious and persistent lie in all of history" and describes concentration camps as "work camps" that didn't have gas chambers.
The Holocaust is one of the most studied and documented atrocities of the 20th century. The Nazi regime murdered approximately six million Jewish people during the war and also targeted other groups including the Roma, people with disabilities and gay people.
Green party spokesman Rod Leggett said Schaefer voluntarily resigned her membership in 2015 and was prevented from renewing it "the minute the party gained knowledge of her views."
"The Green Party of Canada strongly condemns hate speech in all its forms and takes all the steps in its power to eviscerate it. Most recently the party has developed mechanisms to improve the vetting of the nomination process," he said in a statement.
Germany has strict laws against anti-Semitism and hate propaganda in order to prevent another Nazi movement in the country, Loewen said.
But recently, for the first time since the 1940s, candidates from a far-right party were elected to the federal Parliament, and the country is concerned about growing extremism, he said.
"Germany developed these laws as part of its self-definition as a society which promotes more liberal values, all of which are now under threat," he said.
Alfred Schaefer can be seen in a video taken at a neo-Nazi rally on June 30 in Nuremberg in advance of his trial. He says it's "time to exterminate" the Jews, using a derogatory term, and concludes his speech with a Nazi salute.
After the judge in his case saw the video, he was ordered jailed pending his trial, Loewen said.
Loewen argued Canada is not doing enough to combat the spread of neo-Nazi ideas. There is no law against Holocaust denial, which is arguably a form of hate speech, he said.
B'nai Brith Canada has been monitoring the Schaefer siblings' "hateful" online videos for years and was among the groups that notified German authorities about the 2016 video, which was made in Germany, said the group's CEO Michael Mostyn.
"Over time, these videos got worse and worse," he said. "Eventually, we believe that they slipped up. While Holocaust denial may be distasteful and despicable, it's not illegal in Canada, but it is in Germany."
The internet has facilitated the spread of neo-Nazi propaganda and allowed far-right leaders to gain larger followings, he said.
"Whereas only a few years ago, you had some extremists in their basement printing off a couple cardboard copies of their vile Nazi propaganda ... the internet and social media has completely changed the game," he said.
"That's why B'nai Brith in Canada feels it is so important that when you have some of the new leaders of this movement that are out there pushing this vile, dehumanizing propaganda, that they face legal consequences whenever possible."