Gardaí are detaining overnight the seven people arrested as part of a major investigation into money laundering and the activities of the Provisional IRA.
Earlier today the gardaí in Cork seized £2.3 million sterling at a house in the Farran area. A man and a woman were arrested at the house.
In a separate search, gardaí raided a house in Douglas where they seized £60,000 of Northern Bank notes. Gardaí believe it may have come from December's raid on the Northern Bank in Belfast. A second man was arrested there.
Members of the Garda Technical Bureau are continuing to forensically examine a number of locations where money has been found. A third man was arrested during one of these raids.
It is understood that a former Sinn Féin elected representative is among those arrested.
The garda operation has been planned over several weeks and is being directed from the regional garda headquarters at Anglesea Street in Cork City.
Detectives and senior officers from the city have been working with officers from the Criminal Assets Bureau and the Garda Bureau of Fraud Investigation. There are more than 100 detectives involved and the operation is ongoing.
Gardaí are due to meet officers from the PSNI tomorrow to try to establish if any of the €2.3 million sterling or the £60,000 in Northern Bank notes is from the Northern Bank raid.
€94,000 seized in Dublin
Three men were arrested yesterday in Dublin and €94,000 in cash was seized. They are being held at Clondalkin Garda Station.
One is 34, the other is 42 and the other is in his mid-40s. One is from Cork, the other two are from Derry.
They were arrested at Heuston Station yesterday afternoon following a surveillance operation.
Gardaí believe that the man from Cork arrived into Heuston by train, and was in the process of handing over the €94,000 to the two men from Derry to be taken north of the border.
It is understood that the gardaí have been carrying out further searches in the Leinster area.
SF facing 'grave questions': Kenny
The Fine Gael leader, Enda Kenny, has said the arrest of seven people and the reported involvement of a member of Sinn Féin 'raises grave questions for that party'.
In a statement this evening, Mr Kenny called on the leadership of Sinn Féin to make an immediate statement on developments, and on its relationship with those involved.
In particular, he said Sinn Féin must clarify whether any of the people involved acted in an official capacity for Sinn Féin in last June's local and European elections.
Developments 'astonishing', says Rabbitte
Labour leader Pat Rabbitte described the seizure of cash and subsequent arrests as an astonishing development.
Mr Rabbitte said it was of extreme concern that the garda operation was specifically directed at IRA money laundering.
In a statement he said that even at an early stage, it appeared that today's events were particularly significant in the context of the Northern Bank robbery and subsequent denials by IRA and Sinn Féin.
SF advises caution
A Sinn Féin statement advised people to exercise caution and allow the truth to come out.
It said the party had no further information about these arrests and would wait to see how events unfolded before commenting further.
The Ulster Unionist MLA Michael McGimpsey has said the time had come for Taoiseach Bertie Ahern and British Prime Minister Tony Blair to exclude Sinn Féin from the political process.
The DUP's Ian Paisley Junior said Sinn Féin/IRA had been caught red-handed.
