Cousins said on Tuesday that he was called the n-word during the game.
The Boston Celtics have banned a fan for two years for directing racist language toward Golden State Warriors center DeMarcus Cousins on Jan. 26.
In a statement issued on Friday, the Celtics explained their course of action after Cousins alerted the team of the incident that night.
"Immediately upon receiving the complaint, the fan, who was a minor, was ejected," the Celtics said. "The following day, per our policy regarding any reported fan behavior complaint, the team initiated an exhaustive investigation of the incident that included reviewing video from multiple angles and identifying and interviewing numerous fans, security personnel, and police in the immediate vicinity.
"In the course of this investigation, we were able to conclude that the fan had been verbally abusive toward the Golden State bench, but none of the interviewed parties were able to verify the use of racially offensive language, and video evidence proved inconclusive," the team added. "Based on our investigation, the fan was issued a two-year ban from all Celtics games, and is also subject to lifetime probation pursuant to our policy. The punishment for any corroborated discriminatory language used towards any player, employee, or fan at a Celtics home game is a lifetime ban."
Cousins told Yahoo Sports' Chris Haynes that he had been called the n-word on several occasions. While Cousins declined to reveal where the incident took place, Haynes later reported that it was a Celtics fan that night in Boston who directed the slurs at Cousins.
"We were in contact with the Golden State Warriors through this process, sharing our action plan and the final discipline," the Celtics said. "We express the deepest regrets that this incident happened to DeMarcus, as such behavior violates everything the Boston Celtics have always stood for."
Such incidents have been subject to scrutiny since Russell Westbrook's public confrontation with a fan who also heckled him with racist language during the game. Westbrook said the fan told him "to get down on my knees like you used to," sparking the verbal altercation.
The fan was subsequently permanently banned by the Jazz.