Mitchelstown Credit Union in Cork has issued a statement reassuring its members that it is solvent and that all monies are safe.
The move follows a warning from the Financial Regulator that the credit union's financial stability is under threat.
The institution, which has 17,000 members and assets of €100m, has been ordered to cease all business lending.
The Registrar of Credit Unions, Brendan Logue, has warned the organisation that a run on members' savings took place last year and, if that were to happen again, the credit union would find it difficult to survive.
An independent inspector has been appointed to look at the institution's €35m loan book because of concerns about administration, lending practices and provisions for bad debts.
The regulator says members' deposits are protected both by the Government's deposit guarantee scheme and the Irish League of Credit Union own Saving Protection Scheme.