A Bronx middle school teacher who was arrested and accused of sexual assault Wednesday has been charged.

Police say Bill Agosto, 26, who worked as a special education teacher for the Bronx School Of Science Inquiry And Investigation at M.S. 331 in Concourse, is charged with rape and sexual misconduct.

Police say Agosto was involved in a yearlong relationship with a 15-year-old girl, and that she was not a student at M.S. 331.

Department of Education officials say Agosto is being reassigned away from the classroom.

A United Federation of Teachers spokesman told NY1, "Such serious accusations must be investigated. Sexual contact between staff and students is always inappropriate."

Students and teachers at M.S. 331 praised Agosto, and said he was very involved with the school.

"That's just crazy because he teaches health and he taught us not to do that. And he did it," said one student.

"He was a very good teacher in the school. Very nice and polite," said another student.

Authorities say the girl's mother suspected something was going on and reported it to the police.