William Baldet, Prevent coordinator for Leicestershire and Rutland, said primary headteachers had asked him for lesson plans and other resources because they had seen extremist views "start to form at 10 or 11".
He referred to one case in which a 10-year-old had created a website "promoting Nazism and racism" after being radicalised by his grandmother.
“When we start getting into primary schools, then even teachers – even designated safeguarding leads (DSLs) – start to wonder if it’s overreach, for something like Prevent strategy,” Mr Baldet conceded.
But to illustrate how counter-radicalisation was sometimes necessary for primary pupils, he referred to the case of a 10-year-old child who had been indoctrinated to believe neo-Nazi views.
The radicalisation first came to light when the boy entered a T-shirt-drawing competition run by his housing association.
'Swastikas and pools of blood'
“This particular kid drew machine guns, swastikas, dead bodies in pools of blood," Mr Baldet told a meeting at the NEU teaching union (ATL section) conference.
Within the swastikas were the numbers 18 and 88 – numbers which frequently appear in neo-Nazi iconography because they refer to the order in which A, H and H, H come in the alphabet – a reference to Adolf Hitler and "Heil Hitler".
"When we started looking at it, we discovered that although he hadn’t published it, at 10 years old he’d set up a website promoting Nazism and racism," the Prevent official said.
"We spoke to the school who said, 'He’s become more racist in his language. He’s become quite aggressive towards the female teachers.'"
Mr Baldet said it later transpired that the boy's grandmother was a member of a far-right organisation, and had started radicalising him when he was just eight years old.
"What chance was he going to have, in terms of critical thinking skills, to resist what she was saying? And also because he trusted her – why would she lie to him?”
Mr Baldet said that Prevent had created lesson plans for secondary teachers in Leicestershire several years ago, but local primary heads had told him they needed them, too.
"When I did DSL training, I had primary headteachers [saying], ‘This is all great secondary school stuff you’ve got – but I’m telling you as a primary headteacher… the views you’re worried about at that [secondary] school, we’re seeing them start to form at 10 or 11, so where’s our resources?'”
He added: “We’ve finally got around to them, we’re about to launch in about a month or so some primary age-appropriate versions of the same secondary school resources.”