The fallout from the publication in the media in 2003 of agent Stakeknife's identity is discussed in documents newly released to the national archives.
A British Army agent at the heart of the IRA for many years, Stakeknife - widely believed to be Belfast man Freddie Scappaticci - died in 2023 aged 77 in England.
A central figure in the IRA's internal security unit, the 'Nutting Squad', whose job was to root out and kill suspected informers in the ranks, his name was back in the headlines recently with the publication of the Operation Kenova report.
While the report found that he was "a critical person of interest", he had died before prosecutors reached a decision on charges linked to their investigation, and he was never convicted of any Troubles-related offences.
Connected to 14 murders and 15 abductions, the Kenova team said that his activities had probably cost more lives than they had saved.
The newly released files show the impact that the identification of Stakeknife had on Sinn Féin in 2003, with senior Sinn Féin figure Ted Howell saying during a meeting with an official from the Department of Foreign Affairs that it was a "huge internal distraction".
The file shows that Mr Howell also noted that "David Ervine (the leader of the Progressive Unionist Party) had told them that similar allegations would be revealed over the weekend on the (Ulster Volunteer Force)," too.
Stakeknife's impact was clear too from a note of a conversation when Jonathan Powell, chief of staff to British prime minister Tony Blair, was pressing Gerry Adams to support policing policies later in May 2003.
Mr Adams said that this is something that could be looked at when his party managed "to get over some of the difficulties which have been created for the Republican movement by some recent developments, including Stakeknife".
Further newly released documents reference a discussion held in 2001, two years before the publication of his identity, when Hugh Orde, the former chief constable of the PSNI (Police Service of Northern Ireland), called Stakeknife's importance into question in discussions with Irish officials.
When he was one of the top investigators into allegations of collusion between Loyalist paramilitaries and the British security services, Mr Orde told them that while Stakeknife did exist, "he had doubts about his relative importance within the IRA," the diplomats wrote later.
The report goes on to say that the suggestion that he was "operating at the most senior levels, or was a deeply sinister figure responsible for shooting touts on behalf of the IRA was a very attractive story," but something which "he himself clearly seemed to doubt".
Also released is a document which was part of the previously confidential government files released this week to the National Archives, which discusses Stakeknife's circumstances, written by an Irish official just days after the agent had been named publicly in media reports on 11 May 2003.
The document includes a handwritten note that shows that there are "concerns" that Stakeknife might now "also be a danger to himself".
The note was added to a type written report of a phone call between a member of the John Stevens investigation team (who led the Stevens Inquiries into collusion in Northern Ireland) and an Irish official.
The conversation took place on 21 May 2003, and the note is stamped "seen by Taoiseach".
The note states, as in "previous contacts", the Stevens team official confirmed that "as far as Stevens is concerned, Scappaticci is Stakeknife".
When they were asked by the Irish official whether "they planned to interview him soon", the reply was that there were "no plans at this stage" to interview him, and that it was "way too early for that".
The explanation was that "a new unit had been set up, still under Stevens" to handle Stakeknife.
When asked whether they "hadn't any health and safety concerns" regarding him in the period "between now and when they are ready to interview him," the reply was that that it was "not our concern" and "MI5 and the PSNI are presumably looking after him".
Rumours about Stakeknife "moving to this jurisdiction within 48 hours" were put to the Stevens' Inquiries official who is recorded as saying that "Keeler's been talking again".
There is an explanation added in the type written document that "Keeler is Kevin Fulton's real name".
However, then on the margin there is handwritten note saying 'Peter Keeley', referring to the former British agent who used the pseudonym Kevin Fulton.
Underneath the typewritten copy, there is another hand written note too, dated 22 May, from another Irish official, pointing out that "there are concerns" that he might now "also be a danger to himself".
This is followed by "risk of suicide" in brackets.
The Operation Kenova report does not confirm agent Stakeknife's identify and the lead investigator said he had been prevented from confirming it by British government policy.
