Jailed Muslim extremists should be segregated in their own prison wings, say experts.
This would prevent fanatics spreading their hate to moderate inmates, the Quilliam Foundation think tank says.
They believe segregation is needed to prevent non-jihadi inmates among Britain’s growing Muslim prisoner population from becoming radicalised.
The group, which battles extremism, wants a trial run at top-security Whitemoor jail, Cambs, where 51 per cent of prisoners are Muslim, before the units are introduced elsewhere.
Quilliam political officer Jonathan Russell said: “It is essential to prevent radicalisation of other inmates.”
The call comes as new figures show there are 12,328 Muslims in jail compared with just 3,681 in 1997 - a 234% increase.
Mr Russell, speaking after the launch of a report on counter-extremism a decade after the 7/7 attacks in London, warned: “Our prisons are ripe to become recruiting grounds for extremists.
“De-radicalisation and rehabilitation are essential to stop prisons becoming net exporters of terrorism.
“There is a history of prisons segregating groups, such as sex offenders.
“In practice, this would mean having separate wings for Muslims’ convicted of terrorism or extremist offences.
“The Prison Estate has a duty of care for the physical and intellectual well being of all their inmates.
“It is essential to prevent the radicalisation of inmates - both Muslim and non-Muslim - inside jail.
“A pilot scheme would be a positive and Whitemoor is a strong possibility.”
He also called for prison imams to clamp down on radicals.
He added: “They need to explain the difference between the religion of Islam and the ideology of political extremists.”
Quilliam believes ‘a perfect storm’ of factors are making prisons vulnerable to extremism.
These include stretched resources and under-staffing at jails - and British born jihadists returning from abroad.
At least 700 are believed to have left the UK to fight in Syria, Iraq and other countries.
Mr Russell added: “The prison population in general is at risk.
“We need to do preventive work inside the prison with the general population and work to change the ideas of radicals.”
Quilliam also called for more de-radicalisation programmes inside prison.
Currently, some jails run the Contest programme, the government’s counter-extremism scheme, designed to turn inmates away from violent ideology.
However, most prisoners convicted of terrorist offences have rejected the scheme.
Prison Officers Association assistant secretary Glyn Travis said: “Radicalisation is a growing problem.
“There is clear evidence of an Islamic gang culture in some prisons - aimed at young men.
“There are also an increasing number of terrorist offenders, mainly in high security jails.
“This puts unique pressure on prisons at a time of cost cutting and overcrowding.”
In March 2015, there were 42,075 Christians in jail.
The largest Christian group, the Anglicans, has fallen to 16,435, compared to 25,752 in 2002.
A Ministry of Justice spokesman said: “The Secretary of State has asked the department to review its approach to dealing with Islamist extremism in prisons and probation.
“This will be supported by external expertise and will sit alongside the cross government work currently underway on developing de-radicalisation programmes.”