By Dominic Casciani
Tanvir Hussain, Abdulla Ahmed Ali and Assad Sarwar: Airliner plot ringleaders
The High Court has re-imposed a control order on a previously unknown terrorism suspect who is alleged to be part of a suicide bomb "sleeper cell" in the UK.
The man, known only as AM, is alleged to have been an associate of the foiled 2006 plane bomb plotters, even though he was never arrested.
The court says the man remained willing to kill and keep in touch with al-Qaeda figures after the plot was smashed.
The British Indian man, who lives in northern England, denies wrongdoing.
In an unusually detailed judgement, Mr Justice Wilkie reveals a two-year courtroom battle over the restrictions placed on AM's movements and freedoms.
The document reveals that AM came to attention as the security service and police investigated the network of extremists around the transatlantic airliners bomb plot.
AM had travelled to Pakistan in 2004 and 2005, where MI5 believes he received terrorism training in camps linked to al-Qaeda.
'Preparing in UK'
Back in the UK, AM was said to have been preparing to receive detailed instructions for his own suicide attack when police broke up the airlines bomb plot in August 2006. Earlier this year, the plot's three ringleaders were jailed for life.
The judgement reveals that at the time of the arrests, the security service thought that AM "did not show the typical characteristics of an individual preparing to martyr himself". But they later changed their mind.
In April 2007, the Royal Navy stopped a boat off the coast of Oman which included AM and another man. The incident set alarm bells ringing in London and led to further investigations.
Two months later, AM was subjected to a control order, which included a curfew, and a ban on visiting his parents' home.
The Crown Prosecution Service says there is "no realistic prospect" that AM can be put on trial because of insufficient evidence for a conviction.
According to the judgement, officials believe that while he was in Pakistan, AM may have met Abu Obaidah Al Masri, the senior al-Qaeda commander said to have planned the airliners bomb plot.
He is also said to have met Rashid Rauf, a Birmingham man who is also believed to have played a key part. Both men are reported to have since died in Pakistan, although there is no independent confirmation.
AM denies being an al-Qaeda plotter, and told his control order challenge that he opposed suicide bombings. He said that although he was Muslim by heritage, he was not particularly religious, drank beer and went to nightclubs with friends.
But in re-imposing the control order, Mr Justice Wilkie said AM posed a very high risk to the public and national security. The judge said that the man would seek to contact al-Qaeda plotters again, were his movements not restricted.
"In my judgment there is overwhelming evidence that he was a person prepared to martyr himself and, in so doing, to kill large numbers of other people," said the judge.
"He has repeatedly, systematically and carefully lied. It is my judgment that he is an intelligent, capable, well trained, individual who remains committed to terrorist activity."