Potentially dozens, if not hundreds, of estates taken in charge by Cork County Council still have developers or their relatives in ownership of the land and some are still trying to charge residents ground rent.
Council chief executive Tim Lucey has promised to investigate claims made by two councillors that the situation could have significant implications for the upkeep of these estates.
The issue first came to light at a meeting of the Blarney/Municipal District Council when Cllr Kevin Conway said he had become aware of two estates in that area had been taken over by the council, but the land still belonged to the developer.
These are older estates, built in the 1970s, and it appears that up to about four or five years ago when the paperwork to take them in charge was being done there was no provision made for removing the ownership of the developer.
In recent years this has been rectified, but Cllr Conway pointed out that there was a legacy issue with others and this has to be addressed as a matter of urgency.
Council engineers in the municipal district confirmed that Cllr Conway was right.
He said he was concerned that developers or their descendants could step in and prevent the council carrying out maintenance work in such estates.
The matter was again raised at a full meeting of the county council in County Hall by Cllr Conway.
He told Mr Lucey that he viewed this as a very serious matter which had potentially very serious implications.
"If somebody (developer or relative who inherited the land title) was awkward enough they could stop the council or its agents coming into estates doing work such as clipping trees or putting in new public lighting," Cllr Conway said.
He gave details of the two cases he had become aware of in his municipal district and said he was aware of another estate in a different municipal district where the legal representatives of a developer were still demanding ground rents, even though the council had taken it in charge many years ago.
Cllr Seamus McGrath said he was also very concerned about the situation and pointed out that a developer had tried to sell a green space in an estate in the Carrigaline area last year, even though that estate was also taken in charge by the local authority.
"In the end it didn't happen, fortunately," Cllr McGrath told Mr Lucey.
The chief executive said that in recent years the council had ensured that all of the estate ownership was taken into its hands when it took over the running of privately built estates.
He told councillors there was a legacy issue which he would investigate.