Police are examining money, including Northern Bank notes, found in Belfast which they say could be linked to the £26.5m robbery.
The country club is owned by the RUC Athletic Association
It was found at the Newforge Country Club on Friday. Police say the incident may simply be an effort to distract inquiries into the Belfast raid.
A man rang the Police Ombudsman claiming to be a PSNI officer and told them where to find the money.
The RUC Athletics Association has blamed outsiders for leaving the cash.
A police spokesperson said of the Belfast find: "Initial checks would suggest that this incident is an effort to distract the police investigating the Northern Bank robbery and also to divert attention away from events elsewhere over the last two days.
"However, police are taking the find seriously and the material recovered will be examined as part of police efforts to find those responsible for the robbery."
New Forge Country Club is owned by the RUC Athletic Association.
The complex is used by former RUC officers and serving Police Service of Northern Ireland officers.
'Pending a report'
Police have blamed December's Northern Bank raid on the IRA, a charge the organisation has denied.
On Thursday, £2m - £60,000 of it in Northern Bank notes - was seized in the Irish Republic.
Police have released a man held in Cork after the money was found at his house.
On Friday night, two men arrested earlier in the week in Cork in connection with alleged money laundering were released without charge.
Two men from Londonderry, arrested in Dublin on Wednesday, were also released without charge, pending a report to the DPP.
A man was arrested on Friday night after police received reports of cash being burnt in a garden near Cork city.
Mr Adams said there was an attempt to destroy his party
Earlier, 17 bags of sterling bank notes were removed from a house near Cork.
Garda Commissioner Noel Conroy told a news conference an additional £175,000 had been surrendered to police in Dublin on Thursday night.
He said police were still in the early stages of their investigation.
"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."
Sinn Fein president Gerry Adams has said there's been an organised attempt to destroy his party.
"I consider this to be a very serious situation. There's a garda inquiry going on, obviously people should cooperate with that and in time that will do whatever it does," he said in Dublin on Saturday.
"But in the meantime, I think that what is happening is quite disgraceful.
"To listen to some of our political opponents, you would think that Sinn Fein as a party, Sinn Fein as an organisation, that those who vote for our party are criminals and we're not."
In a separate development, a former Sinn Fein vice president, Phil Flynn, resigned from an Irish government committee over his links with a company at the centre of the investigation.
He has also stepped down as chairman of the Bank of Scotland's Irish division.
Mr Flynn said he had done nothing wrong and had no involvement in laundering money for anyone.
Meanwhile, a man arrested in connection with alleged money laundering has been charged with membership of the Real IRA.
Don Bullman, 30, of Wilton, Cork, was one of three men arrested after 94,000 euros were found in a car in Dublin.
A police officer told the Special Criminal Court in Dublin on Friday he believed the notes were part of an IRA money laundering operation.
The cash was in a box of washing powder in a Northern Ireland registered car.
The father-of-three was remanded in custody.