A burglary at a primary school which resulted in hundreds of thousands pounds worth of technology stolen was not discovered until four days later, it has emerged.
CCTV shows thieves ransacking Hillyfield Academy in Higham Hill Road, Walthamstow, on December 27 and returned to steal further items the following night.
The alarm system was temporarily activated during the first break-in, but soon disabled. However it is not known why security firm did not check the school.
Headteacher Matthew O’Dowda only discovered the break-in when the caretaker returned to work on Thursday.
Thieves stole equipment including 700 16GB iPads and 25 of the latest edition iMac computers with an estimated cost of over £250,000.
Once the equipment is turned on and connected to a wi-fi network, it can be traced using GPS technology.
The gang gained entry by smashing a window before kicking their way through a number of doors.
Mr O’Dowda said: “The burglars knew exactly what they were doing. We don’t think it was random, it was a highly-organised operation.
“The school has been completely ransacked and it is hugely disappointing for them to steal from kids. It is the children who will be missing out as a result of this.”
All pupils in years 2 to 6 at the school are given an iPad. There are approximately 900 pupils at the school.
A spokesman for the police said said: "officers were called to the school at 5:30am on January 2 and had established that the alarm system had been deactivated and a forced entry had been made to the building.
"At this early stage, it is believed the suspect or suspects left with in excess of 350 computers and no arrests have been made."
Senior management at the school are set to meet with police tomorrow.