Prince George’s County police and school officials are investigating an incident in which a sexual encounter between students was videotaped in a bathroom at Frederick Douglass High School, and that video was exchanged among other students via mobile phones, according to officials familiar with the case.

The incident came to the attention of school officials last week, and Frederick Douglass’s principal spoke with the student body and notified parents of what happened, said Prince George’s County schools spokesman Briant Coleman. He said school officials also talked with Prince George’s County police to determine whether criminal charges might be warranted, but — at least initially — “they found nothing criminal took place.”

“But the students have been warned, the parents have also been notified, and the principal had a discussion with the student body,” Coleman said. “We’re taking this matter very seriously.”

School and law enforcement officials across the country have long been grappling with the so-called sexting phenomenon, in which people exchange explicit messages or images on their cellphones. On Thursday, two teenagers reached plea deals and a third was convicted in juvenile court in Fairfax County in a case in which they were accused of taping themselves having sex with girls who had not consented to the filming.

Officials familiar with the Prince George’s case, speaking on the condition of anonymity to candidly discuss the sensitive and ongoing case, said the video was of a female student performing oral sex on a male student. The officials said that although the sexual activity seemed to be consensual, investigators were still probing whether charges might be warranted for videotaping it and sending the clip to others. It was unclear who recorded the encounter.

Cpl. Clinton Copeland, a Prince George’s County police spokesman, said he would have to research the incident before commenting.

Coleman said what happened was “considered an inappropriate incident that violated our student code of conduct” and it “involved a cellphone.” In a letter sent to parents that was first reported by the Upper Marlboro Patch Web site, Principal Rudolph Saunders said the incident took place during an after-school activity and involved “consensual sexual acts” and “the inappropriate use of technology.” He wrote that school officials, who became aware of what had happened Wednesday, were “further concerned that the electronic images of the incident are being distributed by students through various avenues.”

“It is extremely important that students are aware that transmittal of electronic images could lead to criminal charges,” he wrote in the letter.