A report on the Northern Bank raid will go further than the British and Irish governments in linking it to the IRA, Taoiseach Bertie Ahern has said.
More than £26m was stolen from the Northern Bank
The Independent Monitoring Commission's report on the £26.5m raid is expected to be published on Thursday.
Mr Ahern was speaking in the Dail on Tuesday after the Irish cabinet met to discuss the report.
He told the Dail that if anything, the report would go beyond anything he has ever said.
Last month, Mr Ahern said that he believed Garda intelligence which suggested the IRA was responsible for the raid.
The IMC - which monitors paramilitary activity - finished its investigation into the December raid last week.
Its report is expected to endorse the police assessment that the IRA carried out the robbery.
Meanwhile, Sinn Fein assembly member Gerry Kelly has called on the Irish government to block any sanctions Sinn Fein may face following the bank robbery.
Mr Ahern met the IMC on 31 January.
PSNI Chief Constable Hugh Orde has blamed the IRA for the raid, a view also backed by the Garda.
However, the IRA denies the claims and, last week, it withdrew its offer of complete decommissioning.
Prime Minister Tony Blair said he accepted the chief constable's view that the IRA was behind the raid.