A Santa Ana high school coach was arrested after allegedly engaging in “unlawful” sex acts with two underage female students and authorities believe there may be more victims, the Orange County Sheriff’s Department said Thursday.

The investigation into Dwayne Jordan Richardson, a 19-year-old “walk-on” girls’ basketball coach at Villa Park High School, began Wednesday after a school resource officer obtained information about sexual misconduct allegations and alerted authorities, according to a Sheriff’s Department news release.

Based on preliminary information, investigators believed there were at least two victims from two separate schools — Villa Park and El Dorado High School in Placentia — and that the alleged sexual misconduct had been going on with at least one of the students since June 2014.

Richardson was booked into Orange County Jail after police arrested him on charges including unlawful sexual intercourse with a minor and oral copulation with a minor.

He posted $100,000 bond and was released from jail.

As of Thursday morning, charges had not been filed against Richardson and a court date had not been set.

Authorities have asked anyone who believed they were a victim or had information about the case to call the Sheriff’s Department Special Victims Unit Sgt. Wade Walsvick at 714-647-7418 or 714-647-7000.

Anonymous tips can also be left by calling OC Crime Stoppers at 855-847-6227, or going to the website occrimestoppers.org.