BUFFALO, N.Y. -- In a letter of apology addressed to general manager Brad Treliving, Calgary Flames coach Bill Peters acknowledged using offensive language in dealing with a Nigerian-born player 10 years ago in the minors.

Without referencing the words he used, Peters wrote in the letter that he knows his comments to Akim Aliu have been the source of both anger and disappointment. The letter was obtained by TSN and posted to Twitter. Peters added that the incident occurred in a "moment of frustration and does not reflect my personal values.''

A statement from Bill Peters, in the form of a letter to CGY GM Brad Treliving:: pic.twitter.com/YouP6ZABrm

— Bob McKenzie (@TSNBobMcKenzie) November 28, 2019

He noted that following the incident, he was "rightfully challenged about my use of language" and "immediately returned to the dressing room to apologize to the team."

Peters did not refer to Aliu by name but said he regrets the incident and apologizes to anyone negatively affected by it, calling his comments "hurtful and demeaning."

The letter was released with Peters away from the team while the Flames and the NHL conduct an investigation into Aliu's allegations.

Treliving, who is overseeing the investigation into Peters, called it a "difficult three days for everyone."

"This investigation we're doing, I know everyone wants this done immediately and the world we live in is immediate,'' Treliving said. "I hope you can appreciate we're trying to do everything we possibly can to make sure we get it right and get all the information that needs to be gotten.''

Before issuing the letter, Peters had not commented or been with his team the past two days while the NHL and the team investigate allegations made by Aliu, who said Peters "dropped the N bomb several times" because he didn't like the player's choice of music. The alleged confrontation happened during the 2009-10 season while the two were with the Chicago Blackhawks' minor league affiliate in Rockford, Illinois.

Peters traveled with the team to Buffalo on Tuesday, a day after Aliu posted his allegations on Twitter. But Peters' whereabouts were unknown, with the Flames saying only that he wouldn't be behind the bench for Calgary's game Wednesday at Buffalo. Associate coach Geoff Ward assumed head-coaching duties as the Flames won 3-2 in overtime.

Peters also was accused this week of punching and kicking players while he was in Carolina.

Hurricanes coach Rod Brind'Amour said Wednesday "for sure that happened" in backing a former player's complaints of Peters physically going after his players behind the bench during his four seasons in Carolina.

Brind'Amour, who was an assistant on Peters' staff, said he was proud of the way players and support staff handled what happened by immediately bringing their concerns to team officials.

"Management handled it directly and never heard of it again and never saw anything else after that," said Brind'Amour, who spoke to reporters in New York before the Hurricanes' game against the Rangers. "So it was definitely dealt with, in my opinion, correctly. ... We've definitely moved past that."

Brind'Amour took over as coach after Peters opted out of his contract following the 2017-18 season. Peters was then immediately hired by the Flames, and he led the team to a 50-win season and a Pacific Division title in his first year.

The Associated Press contributed to this report.