A female Sydney teacher has been charged over an alleged sexual relationship with a 17-year-old male student at an elite school.

Police allege the 33-year-old formed an inappropriate sexual relationship with the teenager and she was charged with indecent assault and six counts of sexual intercourse with person under care between 17 and 18 years.

The teacher was arrested at Camperdown yesterday morning.

She has not been identified and nor has her school in order to protect the student.

The boy reportedly told a school counsellor about his relationship with the teacher and police were alerted by the school.

The teacher, who is pregnant, was granted bail at Newtown Local Court yesterday, the Daily Telegraph reports.

A prosecutor told the court the woman "was in a position of power and she's abused that power … she has exercised a degree of influence over" the student.

She was supported by her husband and her mother posted a $30,000 cash surety to allow her release on bail, the newspaper reports.

She is due to return to court at a later date.