Former Guantanamo Bay detainee Moazzam Begg was released without charge by the British state last week.
The Crown Prosecution Service (CPS) said that the MI5 security service had provided new information just days before his trial was due to begin.
A CPS statement said, “If we had been made aware of all of this information at the time of charging, we would not have charged.”
The human rights campaigner was arrested at his Birmingham home in February in a highly publicised terror raid.
He had travelled to Syria and was accused of attending a terrorism training camp and “facilitating terrorism”.
He has never denied visiting a camp that was training people to resist Bashar al-Assad’s dictatorship.
Moazzam told the Guardian newspaper after his release, “I wanted my day in court. I believe that if I had put my case before a jury I would have been acquitted.”
Moazzam was held for seven months as a Category A prisoner in Belmarsh while people in authority knew he was innocent.
As his solicitor Gareth Peirce said, “There is nothing new that can have been discovered now that was not always crystal clear—that this is an innocent man.”
The “new” information is that MI5 had arranged a meeting with Moazzam and his lawyer before he visited Syria in 2012 and knew he was going. He believes that embarrassment about what might come out in court led to his release.