GLOUCESTER, Mass. — A probe into the Gloucester Police Department and its nationally recognized chief has widened but it still remains unclear what prompted the inquiry.

Mayor Sefatia Romeo Theken said Friday she’s retained Municipal Resources Inc., a Meredith, New Hampshire firm, to conduct an audit of the department.

Theken had already hired two other outside firms to conduct separate audits into “the professional conduct” of Police Chief Leonard Campanello and another officer.

Essex County District Attorney Jonathan Blodgett’s office, meanwhile, also confirmed Friday that it has been asked to review materials by Gloucester city officials in connection with their ongoing audits. A spokeswoman declined to elaborate.

The two officers were placed on administrative leave by the mayor earlier this month for unspecified reasons. The administration says there’s no timeline for the investigations to be completed.

Campanello gained national prominence when in June 2015 he launched the city’s ANGEL program that helps connect heroin addicts to treatment services.

The program, which also allows addicts to turn in their drugs without fear of arrest, has been replicated in dozens of police departments across the country. Campanello was honored by the White House earlier this year for the program.

A lawyer for Campanello said the chief “welcomes any open and fair inquiry” of the department under his tenure.