Police launched an investigation into a high school senior in Kansas after he was accused of a large-scale “sextortion” scheme at his school. The unidentified student allegedly used nude photos of his fellow students to harass them into sending him more, according to the Topeka Capital-Journal.

The student’s classmates, who had their names redacted in the Capital-Journal’s report to reduce the risk of retaliation, said the offender started gathering lewd photos of peers in middle school. He would then use the photos to create false accounts on social networks to intimidate and coerce the classmates into sending him more photos.

According to the report, he may have blackmailed anywhere between 50 and 100 students at Seaman High School. In September, the school district reported the alleged activities to the Shawnee County Sheriff’s Office. The police confirmed that they were investigating the case to the Capital-Journal on Tuesday.

The allegations against the student, if true, would fit into the growing trend of “sextortion,” which is a mostly online phenomenon in which a perpetrator blackmails a victim into sending them sexually explicit material, according to the National Center for Missing and Endangered Children. NCMEC reported a huge increase in sextortion reports to its tip-line between 2014 and 2016.

Kansas is not one of the relatively few states with a specific law against sextortion on the books, but the state did pass laws against the similar phenomenon of revenge porn in 2016. That bill defined revenge porn as intentionally passing along nude images with “intent to harass, embarrass, intimidate, defame or otherwise inflict emotional, psychological or physical harm” on a victim.

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A teenager looks at his smartphone outside the Natural History Museum in Washington on April 8, 2015. A Pew Research Center survey released found that 92 percent of US teens go online daily. NICHOLAS KAMM/AFP/Getty Images