PLACENTIA – A Valencia High School teacher suspected of having a sexual relationship with a student was arrested Wednesday, and police say they are looking for other possible victims.

Rebecca Eileen Diebolt, 35, was arrested on suspicion of sexual contact with a person under the age of 18, a week after a woman told police that she and Diebolt had a sexual relationship that began when she was a student and continued after she graduated, according to a police statement.

The woman told police that in 2004, at the age of 15, she first “formed a relationship” with Diebolt, who was her language arts teacher and swim/water polo coach.

Authorities allege that Diebolt had “multiple sexual encounters” with the student, both in her classroom and at her home after school hours and on weekends.

Investigators believe the relationship continued until 2008, after the woman graduated and began attending college.

The woman contacted the Placentia Police Department on June 4.

On Wednesday, detectives arrested Diebolt while she was exiting her car in the parking lot of a shopping center in the 2500 block of East Imperial Highway. She has been booked into the Orange County Jail system, and is being held in lieu of $100,000 bail, police said.

Diebolt, a Brea resident, has taught at Valencia since 2003, according to the school’s website.

Authorities are asking those with information, or who believe they were victims, to contact Placentia detectives at 714-993-8146.

Contact the writer: 714-796-7939 or semery@ocregister.com