On the trail of al-Shabab’s Kenyan recruitment 'pipeline'
29 September 2013 Last updated at 22:53 BST
The armed siege at the Westgate shopping mall in Nairobi has focused attention on the al-Qaeda affiliate, al-Shabab.
Sixty-seven people were killed after al-Shabab militants stormed the centre on 21 September.
The BBC's Panorama programme had been investigating the recruitment pipeline of young Muslims through Kenya to join the Islamist group based in Somalia.
The programme met up with Makaburi - whose real name is Abubaker Shariff Ahmed - who was placed on a UN Security Council list which banned him from travel outside Kenya.
Peter Taylor reports from Kenya.
Panorama: Terror in Nairobi, BBC One, Monday 30 September at 20:30 BST and then available in the UK on the BBC iPlayer.