BOSTON (Reuters) - A Massachusetts police chief who was honored by the White House earlier this year for his innovative approach to fighting a heroin crisis in his city is now the subject of an investigation and has been placed on leave, officials said on Wednesday.

A statement from the city of Gloucester contained no details on the nature of the investigation of Police Chief Leonard Campanello, and city officials declined to answer questions.

A statement from Mayor Sefatia Romeo Theken said Campanello was placed on paid administrative leave late on Tuesday.

An attorney for Campanello said the probe was unrelated to the police chief's professional duties and that he expected to return to work when the investigation is completed.

"It is our understanding that it has nothing to do with his duties as chief of police," attorney Terrence Kennedy said in a statement provided to the Gloucester Times newspaper on Wednesday. "We intend to cooperate fully with the city to bring this matter to a swift conclusion."

Kennedy did not immediately respond to a request for comment.

Campanello was named a "Champion of Change" at a White House ceremony in April because of his department's approach to drug addicts. The strategy called for persuading them to accept treatment and helping them find treatment options, rather than arresting them for low-level possession offenses.

The approach has been copied by dozens of other U.S. police departments.

(Reporting by Scott Malone; Editing by Bill Trott and Will Dunham)