140 suspected terrorists have been freed from UK prisons: study

More than half of 245 terror convicts have served minimum sentences, are free to walk the streets in a security nightmare for police and intelligence agencies

As many as 140 suspected Islamist terrorists may have been released from UK prisons and are free to walk the streets in a new security nightmare for police and intelligence agencies, according to a latest study.

The study shows that out of 245 extremists convicted and put behind bars, more than half of them have served their minimum sentences and are thought to be entitled to be freed, The Sunday Telegraph reported.

The volume of extremists freed will cause concerns for UK security services and police, who have already complained in a leaked letter that 20 per cent budget cuts "severely impact" on their ability to keep Britain safe from terror attacks.

It is estimated that keeping just one terror suspect under surveillance for 24 hours requires 10 officers. The list of extremists includes terrorists involved in some of the most serious plots targeting Britain in recent years who have either been released or are due to be next year.

Study shows that more than 140 extremists jailed for terror offences in UK are thought to have been freed in new security nightmare for police and intelligence agencies.

According to the newspaper, these include six members of an al-Qaeda 'Dirty Bomb' cell that had plotted an attack on London using limousines packed with flammable gas cylinders and explosives and the wife of a senior figure in the ISIS and a close associate of 'Jihadi John' who was convicted only last year of funding her husband's fighting in Syria.

The study of jailed Islamists going back to 1999 shows 141 have served the minimum jail terms and are as a consequence likely to have been released under licence. Many will have conditions placed on their release including reporting to probation officers, not contacting certain individuals and possible night-time curfews.

Some may be electronically tagged. A further 13 are due to be set free in the next 12 months.

Since 1999, it is estimated just 11 terrorists have been deported or extradited while 82 extremists remain in jail or else have died, according to the Henry Jackson Society, a security and intelligence think tank which has trawled public records for its findings.

Hannah Stewart, who has researched the list for a new edition of a book 'Islamist Terrorism: The British Connections', told the newspaper, "The majority of Islamism- inspired terrorist offenders in this country in the last 15 years have served their minimum custodial sentences allowing for time spent on remand."

The research also shows that the number of criminals convicted of terror-related offences has risen sharply in the past five years. Between 1999 and 2010, 128 people were convicted and jailed for Islamist terror offences compared to 117 people in just five years from 2010 to 2015.