The Irish Government paid SDLP chiefs top-class expenses and mileage during the 1970s, it has been revealed.

Confidential files uncover the unusual arrangement allowing senior party figures to claim payments from Dublin after the collapse of the North's power-sharing executive in 1974.

The documents, just released into the National Archives under a 30-year secrecy rule, also show wary Government officials scrutinised and investigated every claim made by the then dominant Northern nationalist leaders.

In one letter between the Taoiseach's office and the Department of Foreign Affairs, a top aide struck a prudent - if not suspicious - tone as he noted Austin Currie gave a list of SDLP figures "who were alleged to have attended certain meetings with Government members".

Another official said details of the claims "do not tally" with records of meetings and advised further investigation to ensure "the SDLP aren't claiming for something they aren't entitled to".

Former leader John Hume was top of the expenses list, claiming more than £350 on one occasion for several meetings, followed by Austin Currie and Seamus Mallon.

Other notable figures from the party's past, including Hugh Logue, Frank Feely, Paddy O'Donoghue, Joe Hendron, Michael Canavan, Tom Daly, Gerry Fitt, Dan McAreavy and Brid Rodgers all made expenses claims, according to the files.

One memo raised concerns that the Department of Finance-sanctioned "civil service mileage rates" and "Class A" subsistence pay-outs for meals and overnight stays were being drawn from a fund capped at £9,000.

"I understand there is a possibility that this will be exceeded," wrote a Government aide.

SDLP figures claimed for meetings with the Taoiseach, foreign affairs minister, agriculture minister, transport minister and tourism minister.