A Fairfax County high school teacher took illicit videos of “dozens and dozens” of students with a cellphone and cameras hidden around Herndon High School over more than a year, Fairfax County police said Wednesday.

Raphael Schklowsky, 36, of Reston, Va., will face multiple ­charges in connection with the filming of female students in a dressing area and other locations, police said.

The drama teacher is suspended without pay from his job and is jailed after being charged previously with unlawfully filming his au pair and possessing child pornography.

Police said 10 of the victims are identifiable in the videos filmed at the high school and nine of them have been contacted by investigators, but police would still like to hear from other students who think they might be victims. Police said the videos were made between May 2017 and June 2018 and some of the students had graduated.

“Multiple images and recordings of what appeared to be juvenile students in various states of undress were discovered,” said Lt. Col. Tom Ryan, deputy police chief.

Police said additional videos were taken in the New York City area and authorities there are conducting their own investigation. Those videos did not involve students, police said.

Schklowsky’s lawyer, Edward Ungvarsky, declined to comment.

Fairfax County police began investigating Schklowsky in April, after a 19-year-old au pair living with Schklowsky and his family discovered a camera in an air vent in her bedroom, according to a search warrant filed in Fairfax County.

Before the discovery, a previous au pair told the victim that she had discovered a camera in the closet of her bedroom at the house and had confronted ­Schklowsky, according to the search warrant. That au pair did not report the incident to police.

The new au pair was able to take a photograph of the camera she found and send it to police, according to the search warrant. Schklowsky was arrested April 8 and charged with four misdemeanor counts of unlawful filming.

Investigators also searched the Schklowsky home, recovering a camera, a smoke detector camera and a number of other electronic devices.

Investigators found over 3,500 videos on those devices, and Schklowsky was charged in May with 21 felony counts of possessing child pornography. Those videos included the newly discovered videos of the Herndon High School students. Police said it took considerable time to go through the cache of electronics.

Schklowsky had been a teacher at the school since August 2016 and had not worked at other schools in Fairfax County, school district officials said. No complaints had been made about him, officials said.

Schklowsky’s next court hearing is scheduled for Aug. 9.