RICHMOND — The Contra Costa County District Attorney’s Office has charged a Richmond High School teacher with multiple sex crimes in connection with a suspected sexual relationship with an underage student, authorities said Wednesday.

Officials familiar with the investigation had identified the teacher as Israel Ayala-Lopez, 26.

In a statement, police said the district attorney’s office filed charges Wednesday afternoon for four counts of unlawful sexual intercourse with a minor, and four counts of lewd or lascivious acts upon a child for sexual gratification. Ayala-Lopez’s bail was set at $400,000.

The investigation began when the student reported the activity to a school resource officer, Richmond police Lt. Matt Stonebraker said. The officer then told the the school administration and district.

Stonebraker said that based on the student’s allegations, police believe the relationship was sexual.

Police said Wednesday that Ayala-Lopez had been a physical education teacher with the West Contra Costa Unified School District since 2017.

“We are saddened and disappointed to learn about this alleged behavior,” West Contra Costa Unified School District spokesman Marcus Walton said in a statement. “The teacher has been placed on leave, and we are working closely with the Richmond Police Department’s ongoing investigation.”

“The safety of our students is our top priority,” Walton said. “We will continue working with our community partners to ensure all of the children we serve feel safe and supported.”

Staff writer George Kelly contributed to this report.