According to the Sunday Business Post:
Revenue in stamp-duty crackdown
The Revenue Commissioners are cracking down on buyers of new houses and apartments who do not pay stamp duty.
The officers are checking whether buyers are living in the properties. Owner-occupiers who buy a new property do not have to pay stamp duty, but they must continue to live in the property, otherwise they are regarded as investors.
Investors who avoid stamp duty, by claiming to be owner-occupiers and then renting out the property, could be hit with a double tax bill - the unpaid stamp duty plus tax due on any rent paid.