London: MI5 has set up a “lone wolf” terrorism unit as part of one of the biggest operational shake-ups in the organisation’s history, it can be disclosed.

The security agency has already foiled one attack that was in “the advanced stages of planning” using a scheme to “manage individuals judged to present a risk of carrying out violent acts of terrorism alone or in small groups”.

The Government said that MI5 had changed the way that new intelligence leads were processed, developed new ways to identify potential terrorists acting alone, and now had better communication channels with the police.

MI5 has set up Project Danube, a programme for “managing the level of risk posed by low-level subjects of interest”, according to a report.

It is feared that hundreds of extremists linked to Daesh militants, such as Mohammad Emwazi, known as “Jihadi John”, have not been properly monitored by the police and security services.

The MI5 reorganisation was ordered in the wake of the murder of Fusilier Lee Rigby, 25, who was run over and knifed to death by Michael Adebowale and Michael Adebolajo outside Woolwich barracks in south-east London on May 22 in 2013.

A report by the Commons intelligence and security committee (ISC) found that, ultimately, the British intelligence agencies could not have prevented the murder.

However, it was disclosed that the UK security services had tried to intensify their surveillance of Adebowale hours before Fusilier Rigby was killed.

Adebolajo was also a high priority for MI5 during two operations.

The agencies put “significant effort” into investigating him and employed a broad range of intrusive techniques.

However, none of these uncovered any evidence of attack planning.

In its response to the report, the Government disclosed that MI5 had since changed the way it deals with potential terror suspects.

The report states: “Immediately after the attack, MI5 conducted a review of its investigations into Adebolajo and Adebowale and identified the issue of recurring Subjects of Interest as one of the areas for further consideration.

“This review noted that it is common for Subjects of Interest to feature in more than one extremist network.

Assessing and managing the investigation of such individuals is challenging, particularly when the investigations in which they feature do not fully illuminate the nature and extent of their involvement in extremist activities.

MI5 has since developed and implemented ways of identifying subjects of interest who may carry out acts of terrorism alone, outside of the more usual network conspiracy, more likely using unsophisticated methods and with limited prior planning, and has set up a dedicated team to assist with the identification and investigation of such individuals.” It adds: “MI5 has developed a revised methodology for managing individuals judged to present a risk of carrying out violent acts of terrorism alone or in small groups outside of the more usual network based conspiracy.

“This fits within MI5’s existing prioritisation process and has, as a result, already contributed to the disruption of at least one individual who was in the advanced stages of planning to carry out an attack of this type.

This methodology is still evolving and being refined in conjunction with the police.” The Government report states: “During its own internal review, MI5 identified that while the overall process for managing leads was correct and that this process ensured every incoming lead was assessed and recorded on receipt, some adjustments were required to manage assessed leads in the queue,” it said.

“Since the Woolwich attack, these adjustments have been implemented.” A number of questions have been asked in recent days about the security services’ handling of “Jihadi John”, who has appeared in several videos apparently beheading western hostages.

Emwazi was allowed to travel to Syria despite reportedly being part of a network including Samantha Lewthwaite, known as the “white widow”.

Lewthwaite is the widow of one of the 7/7 suicide bombers and is considered to be the world’s most wanted woman.

Emwazi is also thought to have associated with people linked to Fazul Abdullah Mohammad, Al Qaida’s former leader in Africa.

It was also reported that Emwazi had crossed paths with Adebolajo.

It was yesterday claimed that information obtained using torture was used to help foil an Al Qaida plot to bring down two planes.

British authorities intercepted a bomb at East Midlands Airport after being “tipped off” by Saudi Arabian security forces, reportedly following the interrogation by torture of an Al Qaida operative, according to the Independent on Sunday.

Sir John Sawers, the former head of MI6, has said that torture produces intelligence and can be “effective in the short term”.

He said that the security services “set aside the use of torture” because it is against British values, not because it does not work in the short term.