Fianna Fáil is looking for both the operators and the regulator of the National Lottery to appear before the Oireachtas Finance Committee.
It comes after it was revealed four top prizes totalling €180,000 were not included in three scratchcard games since 2014.
The lottery discovered the error during an internal review, and say new controls are in place to guarantee it does not happen again.
Fianna Fáil's Finance Spokesperson Michael McGrath said the revelation raises serious questions for both the lottery operator and the regulator.
Mr McGrath said: "In particular, how could it be that this continued for a five-year period when the prizes were not actually available, but continued to be advertised.
"Why is it that the regulator never discovered this in the course of their work? Why is that the operator of the Lottery, when they discovered this six weeks ago, did not immediatlee inform the public and withdraw the cards from the market?"
Earlier: Lotto chief 'deeply sorry' after top prizes excluded from three scratchcard games
The National Lottery has apologised after a review found four top prizes were not included in three of 178 scratchcard games.
PLI took over the licence for the National Lottery in 2014 and an apology was issued today.
They said the omissions were discovered after an internal review "of all National Lottery products" and were caused "by human error".
A statement explained: "Four top prizes were not included for players to win in three of the 178 scratch card games that it has offered since taking over the licence in 2014.
"Together, the four prizes are worth €180,000 and represent 1.36% of the total prize funds of those three scratch card games."
The statement added: "Lotto, EuroMillions, Daily Millions, digital games and all other National Lottery products were unaffected by these errors.
"The Regulator of the National Lottery was promptly notified of the review and has been regularly updated since. Good causes were not adversely affected."
The games impacted and the omissions in them are:
- In Congratulations Game 186, which was on sale until July 2019, there should have been four top jackpot prizes of €50k, when in fact there were two such prizes.
- In Congratulations Game 223, which has been on sale since April 2019, the website and rules correctly state that there is one €50k top jackpot prize in the game. However, there should have been two €50k top jackpot prizes to align with the approved prize structure. Because of this omission, the game is being withdrawn from sale.
- In Diamond Bingo Doubler Game 125, which was on sale until February 2017, there should have been four top jackpot prizes of €30k, when in fact there were three.
"We are deeply sorry for these errors which should have been fixed before the games went on sale," said National Lottery CEO, Andrew Algeo.
"We are committed to ensuring that our players are always treated fairly. New controls are now in place to ensure this does not happen again.
"We would like to reassure our players by pointing out that the total amount involved is less than 0.01% of all our prizes of the last five years.
"The total value of the missing prizes will now be made available to our players through a special draw."
The group have now announced a New Year’s Special Draw which will take place on January 6.
There will be 180 “will be won” prizes of €1,000 up for grabs.
PLI stated: "At no additional cost, all entrants to the Christmas Bonus Draws will automatically be entered into the New Year’s Special Draw.
"The Christmas Bonus Draws are available to any players of Hampers Sweets and Treats, Merry Money or Christmas Countdown scratch cards after 1st October 2019."
The statement continued: "PLI will fund the total cost of the New Year’s Special Draw and will forego any contribution from additional sales of these Christmas scratch cards compared to 2018, by donating any additional contribution to the charity Jigsaw, the National Centre for Youth Mental Health.
"Good causes will benefit from all sales in the normal way."
A statement from Carol Boate, the Regulator of the National Lottery, said her office became aware of the anomalies in November 2019.
The statement read: "Upon being notified, my immediate priorities were to ensure that the Operator would find and implement a solution to return the value of these prizes to Players at the earliest opportunity and that the Operator introduced effective measures to ensure this doesn’t happen again.
"I fast tracked my considerations of a proposal from the Operator to return the omitted prize money to Players by way of a New Years’ Special Draw, entirely funded by the Operator.
"This proposal was approved. I also determined that the affected scratch card game still on sale should be withdrawn.
It added: "My officials are now examining what breaches of the Act or Licence may have occurred and have written to the Operator to commence the formal process prescribed in the Licence in this regard."