Schools have installed CCTV cameras and microphones in classrooms to watch and listen to pupils as young as four.
The Big Brother-style surveillance is being marketed as a way to identify pupils disrupting lessons when teachers’ backs are turned.
Classwatch, the firm behind the system, says its devices can be set up to record everything that goes on in a classroom 24 hours a day and used to compile ‘evidence’ of wrongdoing.
The equipment is sold with Crown Prosecution Service-approved evidence bags to store material to be used in court cases.
The microphones and cameras can be used during lessons and when a classroom is unattended, such as during lunch breaks.
But data protection watchdog the Information Commissioner has warned the surveillance may be illegal and demanded to know why primary and secondary schools are using this kind of sophisticated equipment to watch children.