The Minister for the Environment, Mr Roche, has asked his Department to carry out an examination into who has been granted contracts for the storage of electronic voting machines and why there are large-scale variations in costs around the country.
The move follows revelations that a number of State-appointed officials who oversee elections have privately bought facilities to store the equipment.
It has also emerged that the bill for storage varies considerably from place to place, with the average costs in Waterford running at four times the national rate.
In a reply to a parliamentary question last Tuesday, Mr Roche revealed that the Department was only aware of the ownership of six storage facilities.
These were listed as: Mr Brendan Walsh and Ms Cara Walsh, in Dublin city; Mr John Fitzpatrick, in Dublin county; Mr Peadar Conlon, in Westmeath; and companies Secure Storage in Donegal, Ashling Microsystems Ltd in Limerick city and Johnstown Properties Ltd in Waterford.
Mr Walsh and Mr Fitzpatrick are official returning officers for elections in Dublin city and county.
Both said yesterday that the State was getting value for money as a result of their moves to purchase premises to store the voting machines.
Mr Fitzpatrick told RTÉ that he had bought a unit in the Tolka Valley Business Park in Dublin which he rented to the Department of the Environment to store the machines.
Mr Walsh has said that he did not stand to make any profit from his rental of premises at Ballycoolin in Dublin.
A spokesman for Mr Roche said that the Minister would publish details of the ownership of the storage facilities when these became available and that, if he considered that a review of the rental variations was required, this would be carried out.
Meanwhile, the owner of the premises in Waterford which has been at the centre of controversy over the cost of storage of electronic voting machines has defended the charges.
Mr Michael Cahillane told The Irish Times that his company had spent €300,000 converting the premises to meet the strict specifications, including wall and roof insulation, set down by the county registrar's office and its electrical consultant for the storage of the equipment.
He said he would have been happy to let the premises at half the existing rent if the registrar's office had been willing to accept the building without the refurbishments.
Mr Cahillane said that the €50,820 rental charge - which was set out in a report given to the Dáil Public Accounts Committee - also included VAT. The net rental income was €42,000.
He suggested that a number of the other storage venues, which have lower charges, could have been secured on short-term leases and would not be subject to VAT.
Mr Cahillane criticised the inclusion of references to Mr Martin Cullen who, as minister for the environment, introduced the aborted e-voting system, in coverage of the controversy about the cost of storage of the machines in Waterford, the minister's constituency.
Mr Cahillane said that the issue had nothing to do with Mr Cullen.
He said that the current rent for the premises was fairly standard.