Ministers 'given Trojan Horse schools warning in 2010'
28 May 2014 Last updated at 19:17 BST
The BBC understands that concerns about Muslim hardliners trying to take over secondary schools in Birmingham were raised with the government in 2010.
A head teacher says he raised the issue three years before an anonymous letter was sent to Birmingham City Council, in which Muslim groups were accused of running Operation Trojan Horse, an alleged attempt to force fundamentalist Muslim values on pupils and teachers.
Sian Lloyd reports.