The Government is hopeful the investigation into the latest leak of Department of Foreign Affairs documents will lead to the source because the pages were torn from an original document.
The leak to the Sunday Independent - which was not published - comes from a document circulated to no more than half-a-dozen senior politicians and a small number of officials in 1994.
The 45 pages, delivered in non-numerical order, were torn from what is known as a Green Book or Box - a collection of information on Anglo-Irish affairs compiled by Department of Foreign Affairs officials.
Because of the limited circulation, Government sources last night said they were hopeful the Garda investigation, headed by Chief Supt Sean Camon, can trace the leak back to the document from which it was ripped.
Senior sources said that, in addition to revealing details of one Anglo-Irish Conference meeting that took place prior to the IRA's August 1994 ceasefire, the documents also show that the deputy leader of the SDLP, Mr Seamus Mallon, strongly opposed the visa application by the Sinn Fein president, Mr Gerry Adams, to the United States.
The contents of the leak are understood to be relatively innocuous and would mean little to the public if published in their present form. They are understood to begin in the period just after the signing of the Downing Street Declaration.
It is also understood that they record the period when Sinn Fein sought "clarification" of the Declaration and record divergence of opinions between Dublin and London on this matter.
What deeply concerns the Government and the Department of Foreign Affairs is the fact that the leak jeopardises the information-gathering by the Department in its formulation of Northern policy and undermines the confidential basis on which individuals talk to officials.
The memos relating to the Government-backed candidate, Prof Mary McAleese, are believed to come from a different source to the one which provided documents to the Sunday Independent.
Jody Corcoran, the Sunday In- dependent journalist who received the documents, said yesterday he was telephoned by three men and instructed to go to a hotel where the pages were contained in a package. Two of the callers suggested they were Fianna Fail dissidents intent on destabilising the Taoiseach. However, this claim is being treated with scepticism in political circles since the documentation has nothing to do with Mr Ahern. He was Minister for Finance in the period to which leak applies and had no involvement in Northern policy.
Having been made aware of the leak, a member of the Department of the Taoiseach telephoned the editor of the Sunday Independent, Mr Aengus Fanning. The Taoiseach's key adviser on Northern Ireland, Dr Martin Mansergh, is understood to have read the documents and the paper agreed not to publish them.
The source of the McAleese memos - which were posted to newspapers - will be much more difficult to trace, though they too were circulated in what one source said was "a relatively tight circle". It is believed they could only have been procured by means of an extensive "trawl" through reams of documentation.
While conversations between a Department official, Ms Dympna Hayes, and Prof McAleese would have been clearly marked in the confidential memos, a conversation between the SDLP councillor, Mrs Brid Rodgers, and Ms Hayes was not obviously defined. Only a person with time to study the texts - or else an individual with a detailed knowledge of the memos - would have come up with the memo relating to Mrs Rodgers.
"The leaks have put at risk vital work that has been done over 25 years by successive governments. It was a reckless, criminal act. Anyone who did this had a malign motive and wanted to cause trouble," one source said. The motive for the leak of McAleese-related memos was to damage her presidential candidacy, but the purpose of the other disclosure is less clear.
Conviction in the District Court for a breach of the Official Secrets Act can lead to six months' imprisonment and a fine of £100; conviction in the Circuit Court can lead to seven years' penal servitude.