A primary school head teacher who used a spy pen to film pupils in the toilets at his school has been jailed for two years and eight months.
Ashley Yates, 45, of Filton, used the device to record images in the toilets of The Tynings Primary School in Staple Hill, South Gloucestershire.
He admitted six counts of voyeurism and three of making indecent images of children at Bristol Crown Court.
The offences relate to seven girls, two boys and six adults.
They came to light after a child found a pen inside a disabled toilet at the school and handed it in to a caretaker.
The court heard that in total the married father filmed 22 adults and nine children and had confessed to his wife that he was a “sexual monster”.
The judge accepted that Yates’ main sexual interest was in adults urinating, but said he must have realised that children were also going to be caught on his camera.
Judge Michael Longman described Yates’ behaviour as “devious” and as a “significant” breach of trust.
During the investigation, additional adult victims were identified by police.
Det Insp Louise Boyce, of Avon and Somerset Police, said: “Yates totally abused his position of trust to feed his own personal desires.
“He set up the recording device in a toilet knowing that both children and adults would be using the facilities.”
She added she had “no doubt” that Yates’ crimes will have “a lasting impact on his victims and their parents”.
A letter to parents on the school’s website said: “These victims came to light after items were seized by police during the course of the investigation.
“If any further victims are identified during the course of the investigation they will be notified immediately.”