Khalid Khaliq, 34, admitted owning a CD copy of the training manual after it was found in a raid at his home on Tempest Road in Beeston, Leeds, in July 2005.

Judge James Stewart QC told Leeds Crown Court that Khaliq would face a maximum two-year sentence.

Khaliq went white water rafting in North Wales with London bombers Shehzad Tanweer and Mohammed Sidique Khan.

The unemployed single father-of-three was one of four people arrested in West Yorkshire and Birmingham by anti-terror police officers on May 9 last year.

The other three – Hasina Patel, the widow of July 7 ringleader Khan, her brother Arshad Patel and Imran Motala – were released without charge a week later.

Khaliq was arrested at a house close to Tanweer's family home in the Beeston area of Leeds.

People living in the area at the time of his arrest said he was a volunteer worker at Iqra bookshop – a centre for young Muslims which formed a focus of police operations following the London bombings.

Fifty-two innocent people died and more than 750 were injured when the bombers – Tanweer; Khan, from Dewsbury; Hasib Hussain, from Holbeck, Leeds; and Jermaine Lindsay, from Huddersfield – attacked three Underground trains and a bus in July 2005.

An al-Qaeda training manual was discovered at Khaliq's home during a raid in 2005.

The charge of possessing a book called Zaad-e-Mujahid (Essential Provision of the Mujahid), which was found in a separate raid last year, was ordered to be laid on file.

Judge Stewart ordered Khaliq to be found not guilty of a further charge of possessing the book The Absent Obligation. Khaliq was bailed overnight to be sentenced at Leeds Crown Court.