There were changes made to the charges imposed on boat owners at Carrick Harbour in September 1985.
Some boat owners may have been entitled to a refund as they had already paid money before the changes were announced.
The changes came into effect after councillors rescinded a decision made by a previous council.
This had imposed charges on boat owners who used the inner harbour.
Most boat owners were not paying charges as a protest against the 1979 Harbours Act.
However, some boat owners had been making regular payments to the Town Hall.
The council had to decide if these boat owners were entitled to a refund or not, and they agreed to seek advice from the auditor.