The suspected incident happened at least five years ago. The news stunned parents and their children who were getting out of class Tuesday.
"I didn't know. It's a surprise for me. I just saw my daughter, but I never heard anything about it," parent Lily Desilva said.
Chaminade school officials said on Aug. 15, it received what it describes as credible evidence that there may possibly have been inappropriate physical conduct by a teacher with former students.
Officials said they contacted the students and hired an independent investigator to review potential witnesses.
School had started Aug. 9, and officials said after they found out about the allegations they removed the teacher from the classroom.
Peggy Barukh said her son was in that teacher's class.
"He seemed like such a nice guy, was really good to my son who just got out of the hospital so it's a bummer," she said. "The kids loved him. The kids really liked him a lot."
The school's president issued a statement that said, in part:
"Chaminade took immediate appropriate personnel action to ensure student safety. After removing the teacher from the classroom, the appropriate child protection and law enforcement agencies were contacted."
The Los Angeles police confirmed there is now an open investigation into the allegations, but they could not provide more details.
An earlier version of this story stated the school was located in Canoga Park. It has since been corrected to West Hills.