Story highlights "Boston's Finest" producer Donnie Wahlberg: "I am so deeply saddened"

The preliminary investigation suggests it was a suicide, Boston police source tells CNN

Officer Pat Rogers was a "really nice, well-liked guy," police source says

The show begins its 2nd season next week

A police officer featured on the TNT reality show "Boston's Finest" apparently took his own life Tuesday, a police source said.

Boston Police officials are not publicly revealing details of the death of Officer Pat Rogers, who appeared in several episodes of the first season of the unscripted series about the pressures of police work.

"The Boston Police department is investigating the unfortunate death of a member of the department," an official statement said. "At this time the circumstances are under investigation and the department asks that the media respect the privacy of the family."

A Boston police source who asked not to be identified because he was not authorized to speak to the media said the preliminary investigation suggested it was a suicide.

Rogers was a "really nice, well-liked guy" who served the people of Boston well, the source said.

The show, which is produced by Boston native Donnie Wahlberg, begins its second season on TNT next week.

Wahlberg tweeted his reaction to getting the news Tuesday night: "I am so deeply saddened tonight. My thoughts and prayers go out to a fallen brother of The Boston Police Dept."

In a statement, TNT said: "We stand with the men and women of the Boston Police Department, and send heartfelt condolences to family, friends and fellow officers."