Ireland has more than 3,000 tax exiles who are required to live outside the country for six months of the year, according to new data from the Revenue Commissioners.
Under a special scheme, individuals can claim non-residency for tax purposes provided they remain outside the state for 183 days a year.
In response to a Dáil question, Minister for Finance Brian Cowen said 2005 was the first year for which the Revenue Commissioners were able to discover the number of tax exiles and the figures showed there were 3,050. The number claiming they were tax exiles last year will emerge in tax returns due to be filed by the end of the month.
Mr Cowen said inquiries relating to tax residency were a feature of "risk-based programmes" operated by Revenue.
The procedures adopted in relation to validating non-resident status depended on the circumstances in each case. "The administration of the validation procedures is a matter for the Revenue Commissioners and the methods used to verify claims to non-residence include a range of tests and an intelligence dimension which for obvious reasons they do not publicise.
"The commissioners have advised me that they have no reason to conclude that there is failure to comply with the rules governing non-resident status," the Minister told Labour TD Mary Upton.
Labour deputy leader Joan Burton said she was surprised by the high number of tax exiles.
"We had never been given any information on the numbers before. I had expected there would be somewhere in the region of 300 to 700.
"It may be that of the 3,050, many are what you might call ordinary tax exiles who have gone to live and work in another country and would be away for a year or two years."
Ms Burton said a "golden circle" of the very wealthy claimed non-residency status "entirely for tax planning purposes". She believed the regulations were too generous and should be tightened.