Ex counterterrorism chief Peter Clarke has warned that the investigation into the Trojan Horse scandal in Birmingham schools has so far revealed just "the tip of the iceberg".
"Of course the Government hasn't got to the bottom of the Trojan Horse affair, nowhere near it," he said.
"You haven't got to the bottom of it until you've proved or disproved whether there is something similar happening elsewhere."
According to the Telegraph, there are concerns that Islamism "is flaring up again and broadening its reach" in UK schools.
A government report released in July revealed a "coordinated, deliberate and sustained action to introduce an intolerant and aggressive Islamist ethos".
According to Clarke, the inquiry found a "sustained and coordinated agenda to impose upon children in a number of Birmingham schools the segregationist attitudes and practices of a hard-line and pollicised strain of Sunni Islam".
"Left unchecked, it would confine children within an intolerant, inward-looking monoculture that would severely inhibit their participation in the life of modern Britain," he said.
Clarke has now countered a recent claim by Education Secretary Nicky Morgan that the government has "got to the bottom of the issue".
"What I put in my report was the tip of the iceberg. There is a huge amount of material which I didn't put in. I deliberately focused on what appeared to be the epicentre. There were problems elsewhere which I couldn't evidence sufficiently in the time available," Clarke has said.
"You've got to look at the roles of Birmingham City Council and the unions and you've got to see where else Tahir Alam [the alleged ringleader] had influence."
A further incident last week at a school inspected during the inquiry last week has increased Clarke's concerns.
Police were called to Welford School in Handsworth after parents complained about course material that challenged homophobia.
"You can't just draw a line after a very brief investigation and say it's job done. The proof will be in what action is taken," Clarke said.
