MIDDLETON, Wis. (AP) _ Nearly 250 seniors at Middleton High School were told to retake a calculus test after suspected cheating.

The Wisconsin State Journal reports Principal Denise Herrmann and Associate Principal Lisa Jondle sent a letter to parents last week indicating they suspected students of sharing photos of calculus test questions.

They wrote the investigation widened after the school received four letters from parents and students indicating such cheating had occurred before and in other subjects.

The letter said students also allegedly took copies of tests from classrooms and planned absences on test days to obtain information from students who took the test.

Middleton-Cross Plains School District spokesman Perry Hibner says no students have been disciplined. The letter to parents said student discipline could include suspensions.