The British government as far back as the early 1970s was informed at the highest level of widespread collusion between the Ulster Defence Regiment and loyalist paramilitaries, new official documents have revealed.
SDLP justice spokesman Alban Maginness said the British government must now answer serious questions about how in 1973 British military intelligence found a "significant" number of UDR soldiers were members of loyalist groups.
A 1973 document, entitled "Subversion in the UDR", reported: "It seems likely that a significant proportion [perhaps 5 per cent - in some areas as high as 15 per cent] of UDR soldiers will also be members of the UDA, Vanguard service corps, Orange Volunteers or UVF." Documents uncovered from the archives also disclosed that in 1975 the then British prime minister, Harold Wilson, and the then Northern secretary, Merlyn Rees, briefed the then Conservative leader, Margaret Thatcher, about the concerns of collusion involving the UDR and RUC with the paramilitaries.
The papers were uncovered by the Derry-based Pat Finucane Centre and Justice for the Forgotten group and published in the Belfast-based Irish News this week, written by one of its senior journalists, Steven McCaffrey.
British military intelligence in the early 1970s reported that the "best single source of weapons, and the only significant source of modern weapons, for Protestant extremist groups was the UDR". It expressed fears that the UDR was loyal to "Ulster" rather than "Her Majesty's Government" and had information that UDR weapons were being used in the murder and attempted murder of Catholics.
A minute of the 1975 briefing with Mrs Thatcher stated that, "The Secretary of State [Merlyn Rees] said that he was more worried by the current sectarian murders than by the bombings in Belfast.
"Unfortunately there were elements in the police who were very close to the UVF and who were prepared to hand over information, for example, to Mr Paisley."
The same document illustrated how some British MPs were receiving letters from constituents calling for withdrawal from Northern Ireland, and how Mrs Thatcher expressed concern that this would lead to bloodshed and therefore was impossible.
Some of the papers also revealed how there was serious suspicion that some UDR soldiers were assisting loyalists to conduct raids of UDR armouries, particularly as many, many more weapons went missing from the UDR than from the regular British army arsenals.
The British army and Northern Ireland Office yesterday had no comment to make on the disclosures at this stage although Mr Maginness said there were serious questions to be answered.
Ulster Unionist Assembly member and former UDR officer Michael Copeland said: "The failures, if any, lie at the door of British military intelligence, who, if they harboured such suspicions, should have taken action."