PUBLISHED: 19:50 GMT, 4 November 2013 | UPDATED: 11:18 GMT, 5 November 2013
The CIA inadvertently gave a terrorist leader the finances and credibility he needed to mastermind a major attack, claims a former spy.
Intelligence officer Morten Storm from Denmark was asked by the CIA to build a relationship with the head of militant group Al-Shabab, the group behind September's attack, and handed over money and equipment on behalf of Western intelligence agencies to cultivate the group's trust.
In 2008 he started to forge close contacts with the leader Abdukadir Mohamed Abdukadir, also known as Ikirma, in a bid to uncover information on potential targets and planned attacks.
When Storm first met Ikrema he was a messenger for Ahmed Abdulkadir Warsame, an al Shabaab leader, according to a report by CNN.
Their first encounter was at a Somali restaurant on the first floor of the Jamia shopping mall next door to the main mosque in Nairobi. Two other jihadists were there with Ikrema.
Storm was meeting with Ikrema in order to get messages and equipment to Warsame. Storm was known to Warsame and to Ikrema as a fellow jihadist.
But the relationship broke down in 2012 when Storm left the CIA due to a ‘disagreement over a mission’ and he now claims the plan to provide Ikirma with money and equipment may have backfired spectacularly.
He also believes that had his relationship with the CIA not faltered he could have helped capture or kill the man believed to have gone on to plan the September attack on Westgate Mall.
Storm converted into to Islam after spending time in prison and developed extreme jihadist views and moved to Yemen in 2001.
He became trusted by fundamentalists and became involved in militant activities, including recruiting soldiers to fight in the Taliban.
However he was recruited by the CIA, MI5 and the Danish intelligence service, PET, as a double agent to information on operations in Yemen and Somalia and prevent attacks in Europe.
When Storm first met Ikirma, he was only a messenger for the jihadists and was sent to pick up an electronic device from the Danish agent by one of the groups then leaders.