The Department of Environment has refused to reveal the location of 40 ghost estates on a Government demolition hit list.
Housing Minister Jan O'Sullivan has identified the 40 unfinished estates which she wants cleared next year.
This is an initial list with plans to add other properties to the hit list where it is clear they can never be sold.
Ms O'Sullivan's department has liaised with local authorities to identify the estates and council officials are now in touch with the banks and developers associated with each site.
Her spokesman said: "The vast majority of these estates are only at the stage where foundations are laid or groundworks carried out. We are looking to return them to green field status."
He added no one lives in the estates on the list but the locations could not be identified until the owners had decided whether to complete them or bulldoze the existing work.
It is understood most are in Leitrim, Roscommon, Longford, Cavan and Offaly. Estates closer to existing large urban developments are more likely to have some commercial value.
The Department of Environment has no powers to force the owners of the sites to demolish existing structures since the estates are privately owned but they hope to reach agreements.
The spokesman added: "Initial talks have already been held with the banks on a collective rather than site by site basis."
Nama owns less than one in five of the country's ghost estates and the remainder are owned by small property developers and the banks.
An allocation of €5m to local authorities to carry out works to make sure the estates did not pose a public safety threat has "nearly all been drawn down".
The Minister is also in talks with local authorities to spend a further €10m from Public Expenditure Minister Brendan Howlin to finish roads, footpaths and public lighting in half-finished estates where some families already live.