The Cunningham family from Cork have yet to collect their winnings from last Saturday's record €16m jackpot.
The National Lottery headquarters on Abbey Street has now shut for the night.
Spokeswoman for the National Lottery, Paula McEvoy, says it has not had any further contact yet from the winners.
Cork couple Paul and Helen Cunningham, contacted the Lottery headquarters yesterday
They have 90 days from the date of the draw in which to claim the prize.
Today, Ms McEvoy said all winners must turn up at lottery HQ to claim their prize with the winning ticket signed by all those who are to share the prize.
She said they would not be allowed to use a back door, but could choose to claim the prize in private and not be identified.
The cheque could not be handed over at another location or to a third party, she said.