A Republican paramilitary guide to intelligence-gathering and campaigning on both sides of the Border has been unearthed by a University College Cork academic researching the organisational aspects of the IRA.
The 73-page manual was drawn up about 1974 by the leadership of the Official IRA. It contains proposals for the recruitment of members of the Defence Forces and Garda Siochana as part of its plans to "overthrow" the Government of the Republic.
The document is known to have fallen into the hands of the group's avowed enemy on the republican side, the Provisional IRA.
A key element of the manual concerns British army interrogation techniques. The Official IRA had somehow seized a British manual on conducting interrogations, which helped the Officials to analyse and device anti-interrogation techniques which subsequently helped the Provisionals.
By the time the document was drawn up in 1974, the Official IRA leadership was already two years into a ceasefire. The document, however, appears to show it was still intent on what it terms the "overthrow" of both the Republic's government and the state of Northern Ireland.
The document is called A Reporter's Guide to Ireland, a title which might have been used simply to hide its illegal and more sinister purpose.
It is understood the Gardai discovered a copy of the document in the possession of a Provisional IRA figure in Donegal some time in the 1980s. It is part of a large volume of republican intelligence and training material which has been seized over the three decades of conflict but until last year the existence of this document had remained hidden.
Ironically, while the Official IRA was a sworn opponent of the Provisionals, it appears its own subversive education manual may have helped the Provisional IRA to reorganise itself after a period of setbacks in the 1970s.
By the late 1970s, the Provisionals re-emerged, under the Northern leadership which largely exists to this day, as one of the most advanced terrorist groups in modern history.
Mr John Horgan, who unearthed it last year during research for a dissertation on republican paramilitary organisation, said: "It is written by clever people and aimed at clever people who would be in charge of intelligence and recruitment.
"On recruitment, it demonstrates the kind of personality qualities needed in potential recruits who would be suited to membership of a secret organisation." Mr Horgan said the manual was almost certainly the basis for the Provisional IRA's internal management manual, the Green Book, dozens of copies of which were found by the gardai and RUC.