In what is thought to be one of the first cases of its kind, the teachers passed on details of the man's appearance, car and registration number after police tipped off the local education authority. In other cases, information on a known sex offender has usually been restricted to head teachers and their staff.
The Liberty civil rights group said so-called neighbourhood notification was "escalating out of control".
But Janet Carr, head of Derwendeg primary school, Cefn Hengoed, in Mid Glamorgan, said: "The parents of my pupils are very nervous ...and want to be aware of all the facts. I know they (paedophiles) are now at risk of approaches from vigilantes, but the answer to that is that they obey the law and leave children alone. The parents have supported me." Other local schools had reacted the same way, she said.
The 42-year-old man was sentenced to two years' jail at a court in Wiltshire 18 months ago for abducting and assaulting two 10-year-old girls. Out on licence, he recently moved to the Caerphilly area, where he was reported by police to be hanging around schools.
Gwent police told education officials at Caerphilly County Borough, which told head teachers. A borough spokeswoman said: "It was left open as to whether head teachers passed the information on to the parents. They are the people who know their communities the best." In the letter, which was copied by the schools with a covering note to parents, the authority's director of education, Neil Harries, named and described the man, before adding: "It should be stressed that this man is dangerous to children and therefore all necessary precautions should be taken..."
The police defended their decision to pass on details and it was up to the education authority what it did with them. "Our responsibility is for child protection," said Detective Chief Inspector Kevin Price.
Jonathan Cooper, legal director of Liberty, said: "This whole notification issue is escalating out of control."
The identifying of individual paedophiles exposed them to risk, and would force them to move on, shifting the problem elsewhere.Reuse content