How Salah Abdeslam escaped following Paris attacks
Panorama reveals how the so-called Islamic State's terror network has been operating secretly in Europe, and Western intelligence agencies' battle to stop it.
The programme has seen secret intelligence which includes transcripts of interrogations with friends of Salah Abdeslam.
One of these friends, Hamza Attou, gave details of how Abdeslam escaped Paris and returned to Brussels.
Panorama - Inside Europe's Terror Attacks is broadcast on BBC One on Wednesday 22nd March at 21:00 GMT. Catch up on BBC iPlayer
24 Mar 2016