Insight for Sunday 25 January 2015

Former jihadist, Aimen Dean gives a unique insight into the workings of Islamic State.

With the rise of al-Qaeda,  he became disillusioned with his comrades’ drift towards terrorism.

(Image: Islamic State flag)

He joined the group – but working undercover for the British government

Despite his defection,  he retains a deep network of contacts within Islamic State and shares that knowledge with the BBC World Service's Peter Marshall .