The bill facing the Exchequer when it pays out for the special savings scheme will be in the region of €3 billion or double original expectations, according to figures released by the Department of Finance.
According to the latest estimates, the 1.13 million holders of Special Savings Investment Accounts or SSIAs are likely to share a payout of €15 billion.
The accounts are due to mature between May 2006 and May 2007.
Financial experts have been advising account holders to increase their monthly savings in the run-up to the maturity date of the lucrative savings scheme, which offered €1 for every €4 saved.