LEOMINSTER, Mass. — A Massachusetts police officer was put on paid leave today after an internal investigation found that he directed a racial slur at Boston Red Sox outfielder Carl Crawford.

Officer John Perrault was suspended pending a disciplinary hearing scheduled for next week at which he could face more severe punishment, and could even be fired, Leominster Mayor Dean Mazzarella and Police Chief Robert Healey said.

Perreault engaged in conduct unbecoming an officer, according to the chief and mayor.

“This is a tough enough world we all live in. Nobody wants to be subjected to that,’’ Mazzarella said at a press conference today at the Leominster emergency management facility. “This shouldn’t happen anywhere, not any baseball park, not anywhere.’’

The officer, who is white, was placed on desk duty after the July 5 incident. He was described as a 5-year veteran officer of the Leominster Police with no prior disciplinary problems.

He was off duty and attending a minor league game in Manchester, N.H.

Witnesses said a heckling fan called Crawford, who is black, a “monday” before a game between the New Hampshire Fisher Cats and Portland Sea Dogs. Crawford said he interpreted the word as a racial slur.

The word can be used as a derogatory term for blacks, and is often associated with Mondays being one of the least-liked days of the week.

Crawford was playing for the Double-A Sea Dogs while rehabilitating a wrist injury.

Crawford alerted stadium officials to the remark, and team management apologized.

Leominster police reached out to Crawford as part of their investigation but did not talk to him, Mazzarella said.

The mayor and chief also issued an apology to Crawford.

Crawford returned to action for the Red Sox on Monday night, in a 5-1 win over the Chicago White Sox.