More than 2,000 children and teenagers were referred to the Government's counter-terrorism programme in 2015/16 - including more than 500 girls.

The first detailed Home Office figures revealed that nearly a third of all those referred to the Prevent scheme were under the age of 15, and over half under the age of 20.

However the figures also show that just one in 20 of those referred receive specialist support to help deradicalise them, and 16 per cent of those drop out of the voluntary scheme.

In one case, a nine year-old boy was referred to Prevent by his teacher after he stood up in class and announced he supported Isis.

Experts said children as young as five or six have been sent for help because of their older siblings' involvement in terror activity, including some who traveled abroad to Syria and Iraq.