BOSTON -- A local fire chief denied knowing that illegal drugs were in his department car on Friday, after a bag of pot was found Thursday.

While cleaning Newton Fire Chief Joseph LaCroix's car on Thursday, firefighters found a small bag of marijuana.

"This discovery came as a shock to me. I want to make it very clear that throughout my more than 36-year career as a firefighter, I have never imperiled the safety of Newton firefighters or the general public by using or possessing illegal drugs," LaCroix said in a statement.

LaCroix said he was cooperating with the police in the city where he resides, Marlborough.

"I deeply regret this incident, and I apologize for any embarrassment this has caused to the members of the Newton Fire Department, Mayor Cohen, and to the citizens of Newton," LaCroix said.

Newton mayoral spokesman Jeremy Solomon told the MetroWest Daily News that the incident is under investigation and no charges have yet been filed.