The Hotel Fjord was sold by the Montenegrin government in 2005 following a high-profile international tender to New Fjord Developments, a joint venture company in which Mr Fingleton is a director and has a 75pc equity share.
However, the site is now lying in ruins and the sale has come under the scrutiny of the courts there after New Fjord was placed into bankruptcy by its creditors.
The Irish Independent understands that Irish Nationwide Building Society (INBS) investigated Mr Fingleton's purchases in Montenegro but concluded they were funded from his personal resources.
Mr Fingleton had a deposit account with the society and the funds were drawn from this source, the probe concluded.
Sources said the issue of Mr Fingleton's purchases in Montenegro was not part of "live" issues passed on to Anglo Irish Bank when it took over Irish Nationwide earlier this year. During his time at INBS, Mr Fingleton held most of his accounts at the society.
There is a major dispute between Mr Fingleton and his former business partner, the Irish developer Louis Maguire, who is suing Mr Fingleton for alleged corporate negligence in relation to the Hotel Fjord deal.
The contract was signed in May 2005 after New Fjord Developments, a special purpose vehicle which is 75pc owned by Mr Fingleton and 25pc owned by Mr Maguire's United European Partners Montenegro (UEP), won the highly coveted bid.
The deal, which required a non-refundable €500,000 deposit, was funded by two subsequent wire transfers from INBS in May 2006 when Mr Fingleton was chief executive of the now nationalised lender.
The two wire transfers originated in Ireland and were cleared through AIB and a bank in Frankfurt before arriving in Crnagorska Kommercijalna Banka in Montenegro.
The first €1.5m tranche stated that the purpose of the funds was "investment of foreign capital". However the second €4m tranche, representing the balance of the €5.5m purchase price, did not state what the transfer was for.
It is understood that Mr Maguire contacted Irish Nationwide directly about the matter, but senior management there was confident any transfers led back to the personal accounts of Mr Fingleton.
Mr Fingleton, who is being sued by the UEP Group, was unavailable for comment last night.
UEP confirmed to the Irish Independent that it was involved in a series of legal actions with the former bank chief.
"We are co-operating with the authorities in Montenegro in relation to this issue and await the decision of the courts on same," Mr Maguire said.
Mr Fingleton is already under severe financial pressure as he tries to meet a €13.6m bill from Ulster Bank.
It got a court order against Mr Fingleton last November after he was unable to repay loans given to purchase a property holding in Cavan.
The bank has since registered judgments over all of Mr Fingleton's properties in Ireland.
The bank said in November it was also concerned over Mr Fingleton's apparent decision to give over his ownership in the Fingleton family home in Shankill, Co Dublin, to his wife.