Once called "Osama bin Laden's right-hand man in Europe," 52-year-old Abu Qatada first entered Britain in 1993, claiming asylum from torture from his native Jordan.
In 1999, the cleric was convicted by Jordanian authorities of conspiracy cause explosions related to bombings at an American school. The sentence carried a life term.
He was convicted of a second crime, that of plotting to bomb tourists, and sentenced to a further 15 years a year later. On both occasions, Qatada was tried in absence.
Qatada's extradition from Britain to Jordan was blocked amid fears testimony against him was extracted under torture.
Following 9/11 and the controversial introduction of the indefinite detention of terror suspects in the UK, Qatada went underground. He became increasingly of interest to the British security services after his sermons appeared on videos found at the property of one of the 9/11 bombers. He was finally arrested in 2002 where he remained until 2005.
He was briefly released in 2005, but re-arrested later that year when the home office came to an "understanding" with the Jordanian government facilitating his deportation on the condition of a fair trial.
However, last month the European Court of Human Rights ruled that Qatada could not be extradited to Jordan due to the same concerns over torture testimony.
Despite Theresa May's insistence that Qatada would be kept behind bars until his extradition was secured, the Jordanian's legal team argued that his detention was illegal, a stance upheld by this week's decision to release him on bail.
But after nearly a decade in jail, why has Qatada not been charged? According to campaign group Liberty, placing Qatada on trial could "embarrass the security agencies" who let Qatada into the country in 1993 believing he was not a threat.
"If there is sound untainted evidence against him Qatada should be tried in a British court," said Shami Chakrabarti, Director of Liberty in a statement. "If the threat he poses is so grave surely that would be preferable to sending him back to an unsafe Middle Eastern kingdom anyway?"
If he can't be sent back to Jordan due to "untainted evidence", then what of charges in the UK? If what's claimed about Abu Qatada is true, if he has incited murder and hatred then why can the UK government not bring him to trial on those charges?
Fighting against Qatada's detainment, Ed Fitzgerald QC, representing the cleric, said that his client had been held for more than six years fighting deportation, and nine years overall on the ground that he was a risk to national security.
Speaking at the recent Special Immigration Appeals Commission, he said: "The detention has now gone on for too long to be reasonable or lawful and there is no prospect of the detention ending in any reasonable period.
"However the risk of absconding, however the risk of further offending, there comes a point when it's just too long. There comes a time when it's just too long, however grave the risks."
According to Roger Smith, the director of Justice, there are two issues on why Qatada has not been charged.
Speaking to the Huffington Post UK, he said: “The first question is what exactly has he done? Incitement seems most likely, but maybe they haven’t they nailed him on something sufficiently specific. The second question centers around what links he has had with the security services."
After keeping Qatada under arrest for the best part of a decade, it appears the UK government would rather find a way of transporting the whole mess east for Jordan to deal with rather than hold a trial in the UK that could prove a huge embarrassment for both current and previous governments responsible for Qatada's incarceration.