Dublin City Council is investigating whether the revamped Clontarf Baths is in breach of its planning permission.
The derelict landmark has been rejuvenated to include a heated seawater pool as well as restaurant cafe.
However the pool is only available for private hire because the owners cannot get insurance to allow public access.
Local councillor Deirdre Heney says Clontarf residents were expecting to use it when it reopened last month.
"People were of the opinion that when the permission was granted that there would be a very fine facility on the seafront that seems to be now in doubt with regard to the planning permission granted and hopefully that matter will be resolved."