Former Guantanamo Bay detainee Moazzam Begg is set to leave prison after of several terrorism charges against him related to Syria were dropped.
Begg, who spent nearly two years at the US detention camp before being released without charge, was facing seven charges including attending a terrorist training camp, facilitating terrorism and possession of a document likely to be of use to a terrorist before the case against him collapsed.
The 46-year-old had spent the last seven months in custody following his arrest on suspicion of terrorist offences following a trip to Syria. He was cleared to leave Belmarsh prison after a judge at the Old Bailey entered a not guilty verdict after the prosecution said there was insufficient evidence against him.
He appeared at the Old Bailey via videolink to hear the case against him being dropped. His trial was due to begin on 6 October.
West Midlands Police and the Crown Prosecution Service (CPS) said the charges against Begg were dismissed after new material previously not known to the investigation emerged which showed there was no longer a realistic prospect of conviction.
Police did not specify what the new material relating to the case was as discussing it would be "unfair and inappropriate".
Assistant chief constable Marcus Beale said "Terrorism investigations are often long and complex. This case was no exception.
"New material has recently been disclosed to police and CPS, which has a significant impact on key pieces of evidence that underpinned the prosecution's case. Our criminal justice system – quite rightly - demands a very high standard of proof.
"I understand this is going to raise many questions. However, explaining what this newly revealed information is would mean discussing other aspects of the case which would be unfair and inappropriate as they are no longer going to be tested in court.
He added: "This case has been investigated in a diligent and professional manner. Today's events demonstrate that the police and CPS continually assess the evidence in terrorism prosecutions and will alter course if that is the right and proper thing to do."
Begg, from Hall Green, Birmingham, was arrested by West Midlands Counter Terrorism Police in February along with three other people.
Police took the unusual step of naming Begg following his arrest in anticipation of the "high public interest to accredited media".
Human rights groups criticised the arrest of Begg as an act of "harassment against Muslim individuals" who were travelling to the civil war-torn Syria in order to provide humanitarian relief.
Begg, who had been open about his trips to Syria, had his passport taken off him by the Home Office in December 2013 after it ruled it was "not in the public interest" for him to travel to the country. He said he was in Syria to investigate claims regarding British and American complicity in torture in the country.
He spent nearly two years in Guantanamo Bay without trial after being detained in Pakistan on suspicion of being a member of Al-Qaida.
During his incarceration at the detention centre, Begg said he was frequently tortured by interrogators who "punched and kicked, forcibly stripped, shaved, violated, spat upon" him. He added he spent most of his time in solitary confinement in a cell "smaller than an average house toilet".
Following his release, Begg successfully sued the UK government for damages after it emerged British ministers agreed to send some British Muslims to the US-run prison despite being aware they risked being abused there.