A Hamilton school trustee running in the federal election for the New Democrats has apologized for making a crude reference related to Auschwitz, reportedly saying she had no idea that it was a notorious Nazi death camp.

In a Facebook note, Alex Johnstone conceded she should not have made her remarks.

"Attention was recently drawn to a comment I posted on social media seven years ago," Johnstone said. "While never intending any malice, this comment was clearly inappropriate. I would like to offer my unreserved apology."

The controversial remarks surfaced via the satirical web-based publication The True North Times which said it had been delving into Johnstone to get a better feel for how the "NDP candidate for Hamilton West-Ancaster-Dundas" speaks when the cameras aren't rolling.

The publication turned up a Facebook posting from April 2008 featuring a friend's photograph of part of the electrified fence and its curved, concrete supports at the death camp in Nazi-occupied Poland.

"Ahhh, the infamous Pollish (sic), phallic, hydro posts," Johnstone commented underneath. "Of course you took pictures of this! It expresses how the curve is normal, natural, and healthy right!"

A visitor walks along a fence at the former Auschwitz-Birkenau World War II concentration camp in Poland. (Paul Chiasson/Canadian Press)

'I didn't know what Auschwitz was'

In an interview with the Hamilton Spectator, she claimed ignorance. "Well, I didn't know what Auschwitz was, or I didn't up until today," she told the newspaper late Tuesday.

When contacted by CBC News Wednesday evening, Johnstone's campaign manager Paul Mason didn't deny the candidate made the statement, and said he "couldn't say whether she said it or not" as he wasn't there at the time.

The federal NDP campaign did not immediately respond to a request for comment.

Johnstone told The Spectator she'd "heard about concentration camps" but noted her Facebook quote indicated she was talking about a hydro post.

She also accused her opponents of "mud-slinging."

A social worker by training, Johnstone is vice-chairwoman of the Hamilton-Wentworth District School Board, having been first elected as a school trustee in 2010. She has a Master of Social Work degree, according to her campaign biography.

Comments on her apology were supportive, with people saying they accepted she meant no malice.

"The competition will dig up anything if they think it can be used to smear the other person," Mike Burgess wrote on her Facebook page.

Wednesday marks Yom Kippur

Others on social media were incredulous that a person with a strong background in education might not have known the role Auschwitz played in the decimation of six million Jews in the Second World War.

Tyler Banham, Ontario President of the Liberal Party of Canada, spoke out on Twitter calling it "unacceptable" that the candidate and school trustee "has never heard of Auschwitz let alone make jokes about it."

Wednesday marked the holiest day of the year for Jews: the Day of Atonement or Yom Kippur.

Johnstone is just the latest of many candidates during this election to come to grief over comments on social media.

Liberal candidate Ala Buzreba dropped out of the race in Alberta's Calgary Nose Hill after four-year-old tweets surfaced of her telling someone they should have been aborted with a coat hanger.

Soheil Eid, a Conservative candidate in Joliette, Que., apologized for a Facebook post that drew a parallel between the words of NDP Leader Tom Mulcair and comments attributed to Joseph Goebbels, Hitler's infamous propaganda minister.