Riverhead High School principal Dr. Charles Regan has been "administratively reassigned by the district pending an investigation into a personnel matter."

The district superintendent wrote in a letter to students that Regan had been reassigned. The letter doesn't state what he will be doing, but it says Regan will not be at the high school.

The Riverhead News Review reported that Regan was an assistant principal at the high school before he was promoted to principal in 2013.

The superintendent asked for patience in the letter, writing "while we understand that there will be questions surrounding this matter, the district is legally prohibited from sharing further details on it."

Riverhead police tells News 12 they'd been contacted by the school district but wouldn't elaborate on the matter.

The district says the assistant principal will serve as acting principal for the time being.