Aliu, who was born in Nigeria, tweeted Monday that Peters directed the N-word toward him in the dressing room several times over his choice of music.
In a second tweet, Aliu said he "rebelled against" Peters due to the comments. He added that in response, the coach wrote a letter to Blackhawks president John McDonough and general manager Stan Bowman to have Aliu sent down to the ECHL despite a strong start to the season.
Flames general manager Brad Treliving said the team is aware of the accusations but won't comment until talking to Peters, according to Postmedia's Wes Gilbertson. Peters was not made available to the media following Calgary's loss to the Pittsburgh Penguins on Monday.
Aliu, a second-round pick of the Blackhawks in 2007, logged seven games in his NHL career - all with the Flames from 2011-13, well before Peters joined the organization.