Two Killarney councillors, one the town's Fine Gael mayor, the other a Fianna Fáil member and a major figure in the tourism industry, have been ordered to appear before a public hearing of the Standards in Public Office Commission.
This is part of "a formal investigation" into an alleged breach of ethics with regard to a land zoning motion in Killarney.
This is believed to be the first such inquiry into local authority members by the standards commission.
The town-centre rezoning would have opened the door for high-density housing, an office block, retail and apartments "and a complete mix of uses", planners said.
Cllr Patrick O'Donoghue (FF), a director of Fáilte Ireland and Tourism Ireland, and managing director of the Gleneagle Hotel Group, and Cllr Sheila Casey (FG), mayor of Killarney and an employee of the Gleneagle group, will be questioned by the commission on March 26th.
The decision to launch a formal inquiry comes after a "preliminary investigation" by the commission's inquiry officer after a complaint from the ethics registrar of Kerry County Council.
This concerns an attempt last March to rezone 20 acres surrounding the Gleneagle hotel and designate it as part of the town centre. The lands are also the site of the INEC conference centre, which hosted the Fianna Fáil Ardfheis last year.
Ms Casey was a signatory to the motion, which sought the rezoning, at the monthly meeting of Killarney Town Council in March 2006. She also voted for it.
Mr O'Donoghue, who did not vote and declared an interest, had lobbied fellow councillors on the issue. He also worded the motion.
The lands are 1.9km outside the town centre, and council management vehemently opposed the town-centre move, saying it would undermine a number of current plans for the town centre and would seriously undermine its viability.
They advised a zoning for tourism facilities in keeping with the current use of the lands and an amendment to this effect was put down by Labour councillor Seán O'Grady.
However, after a brief recess in which Mr O'Donoghue indicated to councillors he wanted to press ahead with the wording of the original motion, the amendment was defeated and a majority voted for the town-centre rezoning.
At a subsequent monthly meeting, town manager Tom Curran refused to allow it to proceed on the basis that the lands were on the rural and urban divide. A further zoning attempt is currently under way, this time omitting the town centre.
It is the first time the Standards Commission, set up in 2001, has used its powers to inquire into a matter concerning councillors.
Chaired by Mr Justice Matthew Smith, the six-member commission includes ombudsman Emily O'Reilly, comptroller and auditor general John Purcell, former TD Liam Kavanagh, clerk of the Dáil Kieran Coughlan and clerk of the Seanad, Deirdre Lane.
A number of Acts have come into play in getting to this point, including the Ethics Legislation and the Local Government Act 2001. Codes of behaviour issued to councillors specifically warn them to take "extra care" in planning matters and to be aware of the public perception.
The hearing at its Lower Leeson Street offices in Dublin will be public and notices will be placed in the media, closer to the date.
The commission does not impose sanctions. However, after next month's hearing, it will report to Minister for the Environment Dick Roche, and if it finds that any breaches are serious enough to be considered offences, a report will also have to be sent to the DPP.
When contacted for reaction yesterday, Mr O'Donoghue and Ms Casey said they were not in a position to comment, given the ongoing status of the investigation.