The New York Times, through a Freedom of Information Act request, has obtained documents containing detailed accounts of how slain Al Qaeda leader, Anwar al-Awlaki, mentored a Nigerian, Farouk Abdulmutallab, who tried to detonate a bomb hidden in his underpants, on a flight from Amsterdam in the Netherlands to Detroit, United States, on Christmas Day in 2009.

Abdulmutallab, referred to as the “underwear bomber” by the U.S. media, is the son of the chairman of Jaiz Bank Limited, Umaru Abdulmutallab. In 2012, he was sentenced to life in prison without the possibility of parole after a defiant guilty plea.

The 200-page redacted documents, which contained information obtained from Mr. Abdulmutallab through extensive interviews, was released to the newspaper after two years of legal struggle.

The Federal Bureau of Investigation (FBI) had kept the account a secret and rejected a request made by an author of a 2015 book on the life of Mr. al-Awlaki, an American-born Islamic cleric, forcing the New York Times to sue to obtain the documents.

In a series of interviews with the FBI, Mr. Abdulmutallab, a wealthy 23-year-old who studied engineering at the University College, London, revealed his journey towards radicalisation and how he sought out Mr. al-Awlaki, who mentored him into becoming a suicide bomber.

Abdulmutallab told an FBI agent about how he first encountered the Al-Qaeda leader through a recorded lecture he bought from an Islamic store in the United Kingdom in 2005. He became enamored by his teachings.

After a trip to the United Arab Emirates in 2009, he said he felt “God was guiding him to jihad”. He travelled to Yemen to meet Mr. al-Awkali, who then had fully embraced violence and was a rising Al Qaeda leader.

From then, Mr. al-Awkali transcended from being his religious hero into his tutor on how to become a jihadist. Mr. Abdulmutallab told agents that the cleric did not only oversee his training in Yemen, but also conceived the plot leading to the failed bomb attack.

According to the report, Abdulmutallab, in series of interviews, described every person he remembered meeting from Al Qaeda in the Arabian Peninsula, as the Yemen branch of the terrorist group is known.

He also provided agents with a vivid description of the layout of training camps, Mr. al-Awlaki’s house and many other Qaeda buildings. According to the New York Times, his descriptions were so precise that they may have aided the U.S.in its drone campaign in Yemen.

He said Mr. al-Awlaki, who was called “sheikh” out of respect, introduced him to other Al Qaeda trainers and bomb makers. The American, Mr. Abdulmutallab told the FBI, taught him how to prepare a martydom video, advising him to “keep it short and reference the Quran”.

Mr. al-Awkali told Mr. Abdulmutallab to hide his trail by first travelling from Yemen to an African country before booking a flight on which he planned to detonate the bomb.

Mr. Abdulmutallab flew from Nigeria to Amsterdam before joining Northwest Airlines Flight 253 to Detroit.

He said the choice of the date for the attack had no special significance and was mainly dictated by ticket prices and flight schedules.

Before he departed, Mr. al-Awlaki sent him a final reminder: “Wait until you are in the U.S., then bring the plane down.”

He said he followed the progress of the flight on the seat-back screen. He waited until he approached the U.S. border and went to the plane’s bathroom to make final preparations for the attack.

He thought of detonating the bomb in the bathroom but wanted to be certain that he was doing so over U.S. soil, so he returned to his seat to check the map for a final time before igniting the explosives.

The bomb did not explode but let out a flame. As he tried to get his burning pants off, passengers pounced on him. One passenger punched him and a crew member threatened to throw him out of the plane.