A number of first time buyers who qualified for the Help To Buy scheme have been ordered to pay the money back.
Over 6,000 people were awarded the grant of up to €20,000 to help fund a newly built home.
However, a new Revenue audit has now found that some of those did not meet the scheme’s requirements.
The Help To Buy scheme was introduced in 2016 to encourage the construction of new homes and to help people get on the property ladder.
The scheme allows first-time buyers purchasing or building a new property to claim a tax refund equal to 5% of the value of the property they are buying.
However, following a series of check-ups, Revenue has found that a number of households were mistakenly approved for the scheme.
The State body is now demanding that these households return the money with interest and potential fines – despite the fact that they were officially approved by the online application system.
Demand letters were issued to a number of households earlier this month ordering them to pay back the money.
Householders have been warned that they will be liable for a fine of €3,000 if it is found that they made their application “carelessly” – and a €5,000 fine if they deliberately gave incorrect information.
The online application is run on a self-assessment basis - with decisions based upon the data inputted by applicants.
This morning, a Revenue spokesperson said there are "no issues with the Help to Buy (HTB) online system which is robust and working correctly."
She said the audit involved targeted checks, carried out to "confirm the eligibility of claims made."
She said Revenue will recover the amounts incorrectly claimed, "where it is clear that despite the details input by the claimant, the eligibility criteria were not in fact met."
Interest will be added to some householder’s bills if they can’t come up with the money within three months of the grant being paid.
Revenue said a "very small number of letters have issued to claimants" to date.
The spokesperson said that where a claimant agrees to repay the "amount incorrectly claimed," Revenue will "take a reasonable approach to the recovery of the monies."
The Minister for Fiance has been made aware of the issue and is due to meet with the Revenue Commissioners.