The mum of a nine-year-old boy who was left feeling “confused and scared” after taking a “lie-detector” test on an iPad at school in a row over graffiti has branded the practice “unprofessional”.

Chanel Brown, whose son Omarion is in Year 4 at Woodlands Primary, Loxford Road, Ilford, has hit out at the unorthodox method used by a teacher to encourage pupils to tell the truth about the incident.

She said: “There was an incident in the boys’ toilets where a teacher’s name was written on the wall and other stuff written about her.”

Ms Brown said her son and several other children were called out to see one of the teachers, who scanned their hands on an iPad lie-detecting app while asking questions about the graffiti.

She said her son’s hands came up showing green, implying he was telling the truth, while others turned red, apparently suggesting they were lying.

Omarion returned to his class but was called out again for another scanning, as, according to Ms Brown, “they didn’t believe him”.

“My son said he was scared and didn’t know what was going to happen to him,” she told the Recorder.

“I have never known of this sort of method being used in schools before, and I am not an old parent.

“My son was left feeling confused and scared.”

She said the children had been even more worried after they mistook a man who had come to fix the photocopier for a policeman.

While the teacher had later apologised for the confusion, and promised not to do it again, Ms Brown branded the practice “scaring the truth out of their pupils”.

A Redbridge Council spokeswoman said: “The school has a positive behaviour policy in place which all staff are required to use and so-called truth apps form no part of this.

“A teacher in the school was speaking to a group of pupils about the incident and as part of his questioning into who the culprit was, it was suggested that the pupils might use a so-called truth app to encourage them to reflect on the importance of telling the truth and taking responsibility for their actions. However, once it became clear that some of the pupils were becoming upset, he realised this approach was not appropriate. The app was being used as a game and a teaching aid.

“On this occasion, a member of staff made an error of judgement. There was no intention to scare, upset or confuse any children.”

The spokeswoman said the app did not show whether someone was telling the truth and this should not have been suggested to pupils.