A Leominster, Mass., police officer is under investigation to determine whether he called Boston Red Sox outfielder Carl Crawford a racial slur during a New Hampshire Fisher Cats game in Manchester last week.

Leominster Mayor Dean Mazzarella confirmed that an investigation is ongoing and that the officer, who was not identified, has been assigned to desk duty.

“We received tips earlier in the week identifying the person,'' Mazzarella said.

Fisher Cats President Rick Brenner isn't concerned where the individual is from.

“I don't want to get into a border war,” Brenner said. “I have been in contact with the Manchester Police Department. We will continue to cooperate with any agencies investigating. If an investigation does turn up the person responsible, that person will not be welcome at the ballpark.”

Crawford was signing autographs before a rehab game with the Portland Sea Dogs, a Red Sox affiliate, at Northeast Delta Dental Stadium when the incident occurred.

The same fan who used the racial slur also yelled “overpaid” and “overrated” during one of Crawford's at-bats, said Crawford, who has not played with the Red Sox this season due to injury.

“He was the only one I had a problem with,” Crawford said to reporters after the game. “People in Boston don't even do that. I don't know what that was about.”

Brenner apologized to Crawford and the Fisher Cats stressed its “zero-tolerance” for foul language after the incident.

Crawford has had a rough start to his Red Sox career since signing with the team prior to the 2011 season. He hit .255 with 11 home runs and 18 stolen bases last year.

“I can understand why people can be upset about me signing a contract and me having the kind of year I had,” Crawford said. “I understand, you know? They love their team. They want you to produce when you sign a contract like that. I can't be mad at them. All I can do is get ready to play this year and try to produce.”

Crawford is expected to return to the Red Sox within a week.

The three-game series last week between the Fisher Cats and Sea Dogs also included Red Sox players Jacoby Ellsbury and Ryan Sweeney, who were rehabbing injuries. The series drew 23,312 fans to break a Fisher Cats' franchise record previously set during a 2009 series in which John Smoltz pitched for the Sea Dogs.

Carl Crawford discusses the incident last week with Union Leader sportswriter Kevin Gray:




After heckler yelled, "overpaid!" Crawford tripled in last week's game: