The National Lottery in Dublin says the claimant has been in touch but is yet to produce the ticket.
A ticketholder in Ireland has claimed a €66m (£50m) share of Friday's EuroMillions jackpot, the National Lottery in Ireland says.
The claimant says they matched the winning numbers of 01, 05, 23, 29, 32 and lucky stars of 01 and 07.
They have been in touch to say they have the ticket but have yet to attend National Lottery Ireland's headquarters in Dublin.
A spokeswoman for the National Lottery in Dublin said: "They have been in contact with National Lottery HQ just to say 'we have got the winning ticket, we would like to come in and claim it'."
The total jackpot for last Friday's draw was £100,765,091, UK National Lottery said.
The massive jackpot prize was shared between two winning tickets, with the other winner claiming the prize in France.
In the UK, six ticketholders matched five numbers and one lucky star to claim £303,465.
The win comes just days after a missing lottery winner came forward to claim £33m - ending the three week search for one of two successful tickets in the 9 January National Lottery draw.
The massive jackpot prize was shared between two winning tickets, with the other winner claiming the prize in France.
In the UK, six ticketholders matched five numbers and one lucky star to claim £303,465.
The win comes just days after a missing lottery winner came forward to claim £33m - ending the three week search for one of two successful tickets in the 9 January National Lottery draw.