Some of the comments made by Brad Badiuk, an electronics teacher, concern aboriginal people generally. Others targeted Derek Nepinak, the grand chief of the Assembly of Manitoba Chiefs (AMC).
The controversy started when another teacher posted an article on her Facebook page about John Ralston Saul's book, TheComeback, which contends that repairing the relationship between First Nations peoples and the rest of Canada is a pressing issue.
In response, Badiuk put these posts (taken verbatim) on Facebook, "Oh Goddd how long are aboriginal people going to use what happened as a crutch to suck more money out of Canadians?
"The benefits the aboriginals enjoy from the white man/europeans far outweigh any wrong doings that were done to a concured people."
Another line read, "Get to work, tear the treaties and shut the FK up already. My ancestor migrated here early 1900's they didn't do anything. Why am I on the hook for their cultural support?"
Other comments Badiuk posted take aim at AMC leader Derek Nepinak.
"He wears feathers on his head and calls himself the Grand Chief. You see he had an idea. Indians have no money. You have money. So he could get his hands on your money, that would solve the problem of indians without money," the comments read.
Kevin Hart, who works with the AMC, lodged the complaint about the comments, calling them racist and hurtful, and demanding the school division take action.
"It just shows that we have so much more to go, that even a teacher that works in a school division, we [even] have to educate those people," he said. "I think it's worse, especially when we have educators ... leading and teaching the young minds of this country."
Nepinak was blunt in his response.
"If racists are going to come forward like that and make comments like that, but yet are still tasked with teaching our young people, then we got a responsibility to stand in the way of that."
Nepinak also acknowledges the relationship between the aboriginal community and others still requires work.
"I come from a humble place, a respectful place to recognize that there's a lot of people suffering from ignorance."
CBC's attempts to reach Badiuk for comment were unsuccessful.
School officials could not say how long the investigation would take or whether Badiuk might face discipline.
"It's obviously really disheartening," said Mark Wasyliw, chair of the board of the Winnipeg School Division.
"We are a very diverse school division. We have a huge population of aboriginal students and these types of allegations are always concerning and demoralizing for staff."