Police charged 34-year-old Paul Johnson-Yarosevich of Acton, Maine, on Monday with prohibited use of computer.
The investigation started in December after the parent of a pre-teen girl told police about the contact. Police said the girl thought she had been communicating with another female student around her age.
The Manchester School District says Johnson-Yarosevich, a physical education teacher employed by the district since 2005, was placed on leave before his arrest.
A phone number listed for him rang unanswered Monday. It wasn’t immediately known if he had a lawyer who could comment on the charges. Police say he’s being held on $5,000 bail.