Convicted Islamist terrorists are exploiting the growing gang culture in top security jails, fuelling fears that they are trying to radicalise other inmates and foment unrest.

The emerging contacts between terrorists and existing gangs in jails is occurring as the Prison Service is expecting a big increase in the number of terrorists it must look after in the next few years. The growing concern among senior Whitehall officials at the danger of Islamist terrorists seeking to radicalise other prisoners in eight top security jails is disclosed in a Ministry of Justice document.

It reveals that officials are looking at whether more high-security prison accommodation and high-security courts will be needed to cope with the predicted number of terrorists being prosecuted. It also outlines worries within the department over the radicalisation of nonterrorist Muslim prisoners and other offenders in the high-security estate.

“The numbers of convicted and suspected terrorists entering the high-security estate is becoming ever higher. Concerns over the effects of radicalisation are growing,” the paper says. “Early work needs to be done to challenge terrorist behaviour and the threat of radicalisation.”

The document, The National Commission Plan 2008/2009, admits that the Prison Service currently has no specific programmes aimed at the risk posed by extremism within top-security jails.

“There is an urgent requirement to understand the custodial behaviour of this group of offenders and its potential impact on other prisoners,” the paper says.

Last year jail watchdogs gave warning of the effect of an influx of rival groups schooled in gun and gang culture.

There are more than 130 terrorist prisoners in England and Wales, including 113 category A prisoners. A Whitehall document released in November said that the number of terrorist prisoners is projected to rise to 1,600 by 2016-17.

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