Braydon Mazurkiewich was one of about 30 people who were seated in an area directly behind where Harper stood at a rally of party faithful.
The group served as a backdrop for cameras recording Harper's speech.
But before the speech began, a man approached Mazurkiewich and he was moved to the far side of the room.
Mazurkiewich was ousted as the head of the provincial party's youth wing in 2012 after posting comments about aboriginals on Facebook that he later admitted were racist.
Mazurkiewich did not return a message requesting an interview Thursday night, and one of the prime minister's media handlers said Mazurkiewich would not do interviews after the speech because he was lining up for a photo with Harper.
Mazurkewich made headlines in 2012 when he complained on his Facebook page about a planned urban reserve for aboriginals in Winnipeg.
He wrote that the land, a former military base, was "built for hardworking men and women of the military, not freeloading Indians."
Within hours, provincial party officials asked for and received his resignation and Mazurkiewich apologized.
But some aboriginal leaders did not accept his apology, and he drew more criticism when he explained his opposition to the urban reserve by saying he felt there was too much violence on reserves that did not fit in with Winnipeg.
Also on HuffPost