A Toronto family studies teacher has been charged with sexual exploitation for allegedly having an inappropriate relationship with a student.

Police said Crime Stoppers received a tip early this month revealing a romantic and sexual relationship between a female teacher and a male student, aged 15 or 16.

The courtship allegedly began soon after the teacher started working at Nelson A. Boylen Collegiate Institute in September 2005. It was her first teaching job, police said.

The teacher, who is not married, is seven months pregnant.

"The board is aware that this teacher is pregnant, but any connection between this alleged offence and that, obviously we have no idea," Toronto District School Board lawyer Grant Bowers told CTV News.

But the student has since left the school, raising suspicions.

"Early indications are that the reason the student left school is directly related to that pregnancy," Toronto police Det. Peter Duncan told reporters.

Police say the families of the teen and the teacher have been aware of the relationship.

Students at the school, located near Highway 401 and Jane Street, were sent home with a note on Friday explaining the allegations.

The notice says the teacher has been placed on home assignment and has not been in contact with students.

"It is important to keep in mind this is an allegation and therefore guilt should not be assumed," the letter reads.

News of the charges shocked many at the high school.

"She's a very nice teacher, she's always positive about things," said student council president Abby Theva. "In fact, I don't believe what is going on right now, I think it's all just false."

On Tuesday police arrested 35-year-old Paola Queen and charged her with one count of sexual exploitation.

She was released with conditions she not attend the school.

Queen is to appear at the Finch Avenue courts on April 17.

With a report from CTV's Austin Delaney