More than 350 convicted and suspected terrorists have been freed from prison over the last seven years, figures show.
There were 41 convicted terrorists released from jail in the year to June as well as 12 suspects who had been held in custody but not sentenced, according to analysis of Home Office figures by the PA news agency.
Overall, 353 terror criminals and suspects have been released from prison between June 2012 and the same period in 2019, of which 245 were convicted of offences.
The remaining 108 were suspects held on remand in prison but later released without charge or acquitted after facing court.
It is not known how many more have been released in the last six months. The Ministry of Justice (MoJ) said it was unable to provide the latest figures.
The news comes less than a week after the London Bridge terror attack which claimed the lives of Saskia Jones and Jack Merritt.
Convicted terrorist Usman Khan embarked on a killing spree while attending a prisoner rehabilitation programme at Fishmongers’ Hall last Friday afternoon.
The 28-year-old, armed with two knives and wearing a fake suicide vest, was tackled by members of the public, including ex-offenders from the conference, before he was shot dead by police.
Khan, a British national from Staffordshire, was released from prison on licence in December 2018, halfway through a 16-year prison sentence after he was convicted of terror offences in February 2012.
He was part of an al Qaida-inspired terror group – linked to radical preacher Anjem Choudary – that plotted to bomb the London Stock Exchange and build a terrorist training camp on land in Pakistan-controlled Kashmir owned by his family.
A list of other potential targets included the names and addresses of the Dean of St Paul’s Cathedral in London, then London mayor Boris Johnson, two rabbis, and the American Embassy in London.
He was one of around 3,000 live subjects of interest being monitored by MI5 since his release, but all freed convicted offenders are the focus of lower level investigations, PA understands.
It is understood a risk assessment was carried out by police and probation officers on Khan’s latest trip to London and attendance at the event, as would be standard practice with all prisoners and offenders on licence in such circumstances. Police and probation staff would have been at the event.
The MoJ – which was involved in the event organised by the University of Cambridge and the Learning Together programme – said it could not comment on the risk assessment while the police investigation into the incident continued.
The latest attack – which took place just weeks after the terror threat level was lowered from severe to substantial – prompted concerns over the length of sentences terrorists faced in prisons and the conditions they were subjected to on release.
As a result, the Government has launched an urgent review of currently serving prisoners at risk of radicalisation as well as convicted offenders who have since been released from jail is ongoing.
Police, security services and probation teams are examining the files of around 200 known extremists with some reportedly facing bans from large towns and cities.
About 70 of the cases relate to convicted terrorists freed on licence before the end of their sentences.
The files of another 150 are said to also be on the list as part of the review – including inmates approaching release and suspects who were arrested under terrorism laws but later convicted of lesser offences and are now free.
MI5 has around 600 live investigations at any one time and since the Westminster terror attack in March 2017, 25 plots have been thwarted by police and security services.
Since the September 11 2001 terror attack, 3,769 people were arrested for terrorist-related activity and 525 were convicted under terror laws, according to the latest figures.
Some 61% of those arrested (2,781) said they were British or had a dual nationality.
The number of arrests has dropped 20% in the last year, from 259 people detained for terrorism-related activity in the year ending September 30 compared with the 325 arrests in the same period in 2018.
Of these, 96 (37%) were released on bail or released under investigation – meaning they were not subjected to any restrictions while inquiries into the offences continued.
There were 88 (34%) charged and 62 of these were for terrorism-related offences.
A further 14 (5%) received a caution, were recalled to prison or handed over to immigration authorities and 60 suspects (23%) were released without charge.
Overall there were 224 people held in custody for terrorism-related offences in the country in the year to the end of September.
The “vast majority”, 77% (173), were branded as holding Islamist-extremist views, the data report said.
A further 17% were categorised as holding far right-wing ideologies.
Commonly, sentences are consistently less than four years.
Just one offender in the last year was handed a life sentence, down from seven in the previous year, and the number of long-term sentences of more than 10 years also fell.