Former Marlboro Police Chief Robert Holmes is facing allegations of sexual assault against a minor, authorities say.

Holmes is accused of sexually assaulting a 12-year-old girl from 2005 to 2007. Prosecutors say the investigation into Holmes' alleged sexual relationship with the minor started in December of 2007. He left the township at the end of 2008 because of performance issues, police sources say.

The 61-year-old Holmes served on the police force for 36 years. If convicted, he could serve up to 20 years in state prison. Holmes' attorney declined to comment.