The cameras were installed two months ago
A head teacher has defended installing CCTV cameras in a secondary school's toilets, which led to a teenage girl being withdrawn by her angry father.
The cameras have been put in to tackle the misuse of paper towels and soap, says Aeron Rhys, head of Ysgol Dyffryn Teifi in Llandysul, Ceredigion.
The pupils's father called it an "outrageous invasion" of privacy.
But Mr Rhys said children had been concerned about cleanliness, and the cameras had "done the trick".
The leader of Ceredigion council has also supported the move.
Anthony White, from Llandysul, has withdrawn his 14-year-old daughter from the school over the issue.
He told the Carmarthen Journal that the cameras at the Welsh-medium school were an "outrageous invasion" of privacy.
But Mr Rhys denied it was an invasion of privacy or an over-reaction.
He said pupils had "expressed concern that the wash basin areas were not being respected by a small minority" of children.
He said some pupils had engaged in "horseplay" in the past and had misused paper towels and soap.
He added: "The CCTV was installed to monitor these areas and it's done the trick. There's been a significant improvement.
"Obviously this decision was not taken lightly and cameras were installed in the best interest of pupils.
"It was discussed in school council and with pupils beforehand."
He said the cameras had been in place for two months.
The leader of Ceredigion council Keith Evans, who represents the town and is a school governor, supported Mr Rhys' decision.
"Toilets can be areas where misbehaviour occurs. In this case CCTV was installed, in the main, to overcome concerns about the misuse of paper and soap," he said.
Mr White told the Carmarthen Journal that he thought the decision was an "invasion of her privacy".
"The whole place is like they're on Big Brother. There are cameras all around the school, outside and in the corridors," he said.
Ceredigion council said the CCTV footage in the toilets was only examined if an incident was reported.
It said it understood the equipment was installed "owing to pupils and cleaning staff reporting incidents that were of major concern to them".