Image copyright Pacemaker Image caption Fred Scappaticci strenuously denies he was an Army agent within the IRA

Files covering the activities of the army's top agent within the IRA, codenamed Stakeknife, have been prepared for the Public Prosecution Service of Northern Ireland (PPSNI).

It follows a three-year independent investigation, Operation Kenova.

Stakeknife is alleged to have been west Belfast man Freddie Scappaticci, 73, who was arrested for questioning in the course of the investigation.

He has denied being Stakeknife, who worked within the IRA in the Troubles.

The files - on which prosecution decisions will be made - cover a number of individuals, including those who were in the IRA, army and security services.

Operation Kenova was headed by Jon Boutcher, who was, until recently, the chief constable of Bedfordshire.

A statement said: "Jon Boutcher, the head of Operation Kenova, and his team has prepared files containing evidence regarding a number of offences outlined in the investigation's terms of reference - including murder, kidnap, torture, malfeasance in a public office and perverting the course of justice.

"Those files are now in the process of being made available to the Public Prosecution Service for consideration.

"It would not be appropriate to go into further detail regarding that evidence, or the number of individuals involved, until that consideration has taken place.

"A full report of Operation Kenova's findings will be published at the conclusion of all legal proceedings."

Image caption Mr Scappaticci left Northern Ireland when identified by the media as Stakeknife in 2003

Mr Boucher's investigation was launched amid concerns the agent was involved in kidnap, torture and murder and looked at whether it was sanctioned by his army handlers and the security service MI5.

Up to 50 killings were looked at, some as far back as the 1970s.

Mr Boutcher promised to go "where the evidence takes us" and gathered thousands of documents and interviewed more than 120 people, including the head of MI5 Sir Andrew Parker and former chief constables in Northern Ireland, Sir Hugh Annesley and Sir Ronnie Flanagan.

He was tasked to undertake the inquiry by the PSNI.

Freddie Scappaticci was named by the media as Stakeknife in 2003, having been the head of the IRA's internal security unit, whose chief task was to root out informers.

It is believed the file submitted to the PPSNI deals with him and a number of other individuals.

It is likely to be some time before decisions are reached on whether anyone can be charged on the basis of the evidence gathered by Mr Boutcher and his team of investigators.