The Ministry of Justice has blocked plans for an academic study into why prisoners convert to Islam and how it can lead to radicalisation.
The proposal had the support of Max Hill, the independent reviewer of terrorism laws. Other supporters of the three-year project are dismayed by the decision and believe that it is because the prison service did not want outsiders studying such a sensitive area.
"The scale of radicalisation should not be overestimated but in certain prisons it is certainly growing," a source said. "The corporate culture of the service is defensive and they will have been concerned about what this proposed project will discover."