Police were questioning a man today over a suspected attempt to groom teenagers on the internet.
Around 40 children at Falmouth School and Penryn College in Cornwall are believed to have been targeted over the internet.
A 28-year-old local man was arrested earlier this week on suspicion of making indecent images of children and sexual assault.
He was in custody at Newquay police station, Devon and Cornwall Police said.
The arrested man does not work at either school but had access to children through a club for young people where he helped out, reports said.
Police and staff from Cornwall children's social care are carrying out the joint child protection investigation into "inappropriate behaviour on the internet by an adult", police said.
A spokesman added: "The investigation has identified a number of young people connected with Falmouth School and Penryn College.
"None of the activity being investigated by the police took place in either of the two schools."
Staff from the Children's Services Authority, Falmouth School and Penryn College are in close contact with Devon and Cornwall Police.
Officers from the council and staff from both schools are also working with other agencies to provide support for any pupils and families affected by the situation, police said.
A dedicated telephone line has been set up for parents and carers who have concerns or whose children can help with the investigation.
The number, available from 9am to 8pm, is 0800 731 3247.Reuse content