TAMPA, Fla. (WFLA) — A former substitute teacher accused of having inappropriate relationships with students in two Tampa Bay counties was ordered to be held in jail without bond on Thursday.

Joseph Prevatte, 39, is under investigation for multiple alleged inappropriate relationships with students in Hillsborough and Manatee counties.

In Hillsborough County court on Thursday, Prevatte’s defense attorney was informed of new developments in the case. The former substitute had child pornography on his phone, prosecutors said, and they’ve obtained a warrant to search a second phone.

In Manatee County, Prevatte was accused of sending sexual messages and a nude photo with his genitals cropped out to a student. Deputies said this happened after the teen followed him on the social media platform on his first day subbing at the school.

He was also accused of sending sexual messages to a high school student in Hillsborough County and having sexual interactions with them. He is also under investigation in a case involving an elementary school-age child, according to the Hillsborough County Sheriff’s Office, but that case has no connection to his role as a substitute teacher.

Authorities believe there may be more victims. Anyone with information is asked to contact the Hillsborough or Manatee County sheriff’s offices.