More than £2m seized by Irish police has been taken for forensic examination to see if it is linked to the £26m Northern Bank raid in December.
The money was taken away for examination
Seven arrests were made in Cork and Dublin during a series of raids in which the money was seized, including £60,000 in Northern Bank notes.
A Cork man has appeared in court charged with IRA membership in connection with the find.
Two people arrested in Dublin have been released without charge.
Earlier, Irish police chief Noel Conroy said those arrested included suspected members of the IRA.
Seventeen bags of sterling bank notes were removed from a house near Cork.
Garda Commissioner Conroy said an additional £175,000 was surrendered to police in Dublin on Thursday night.
He said they were still in the early stages of their investigation.
Garda Commissioner Conroy said the robbery was a line of inquiry
"We see a subversive element in the movement of this money," he said.
"We are following quite a number of lines as to where the money may have come from, and naturally enough, one of those relates to the Northern Bank robbery."
However, he refused to speculate on whether there was any definite link with the Northern raid.
He said the IRA was behind the alleged money laundering operation and at least one dissident republican was among those arrested.
Speaking in Spain, Sinn Fein President Gerry Adams said people should not be in a rush to blame republicans.
"I would urge people to be very measured," he said, adding that it was not the time "for making knee jerk judgements or trying to beat up on Sinn Fein".
The robbery at the Northern Bank's headquarters in Belfast was one of the biggest cash raids in UK history.
Police on both sides of the border have blamed the IRA for the robbery, which the paramilitary organisation has denied.
Wednesday 1600 GMT Dublin Three men arrested at Heuston Station and 100,000 euro seized
2100 GMT Cork Raid in Passage West, one man arrested
Raid in Douglas, one man arrested £60,000 in Northern Bank notes seized
Thursday 0900 GMT Premises at an undisclosed location in outside Cork raided
1100 GMT A house in the Farran area of Cork is entered and £2.3m is seized. A man and a woman are arrested
1800 GMT Raids at undisclosed location in Leinster, they end at about 2030 GMT
Search operations in Londonderry
Two men were arrested on Wednesday night during house raids in the Douglas and Passage West areas of Cork.
Another three men were also detained at Heuston train station in Dublin. It is understood that two of the men are from Derry and the third is from Cork.
A man and a woman were arrested in a follow-up operation in the Farran area of Cork on Thursday morning.
Further police searches took place in the Leinster area on Thursday night, as well as PSNI raids in Londonderry.
Police in Derry were attacked by stone throwers, with one officer being treated for concussion after he was struck on the head.
Two men from the city were among the seven arrested by Irish police.
The suspects, who are being detained under Section 30 of the Offences Against the State Act, can be held for 72 hours before they are charged or released.
The money which was seized in Cork is being transferred to Dublin, where it will be examined by the Garda Technical Bureau.