Four ticketholders who each won £1 million in the New Year's Day EuroMillions Millionaire Raffle have not yet come forward to claim their windfall.
A ticket with the selection of HZH113111 was purchased in the Aylesbury Vale District of Buckinghamshire, another with the selection HZH020202 was bought in the London Borough of Haringey and a ticket was sold in the Borough of Dacorum in Hertfordshire with the selection HYW756634.
The final missing millionaire purchased their ticket in the Blaenau Gwent & Torfaen area of South Wales and it features the selection HYW536466.
So far just 21 of the 25 ticketholders who won £1 million in the special New Year's draw have come forward.
The remaining ticketholders have until 11pm on June 30 to make their claim.
A National Lottery spokesman said: "Players across these areas should now be checking their tickets - they could be worth £1 million!
"Try and remember back to New Year's Day and where you may have placed that lucky ticket for safe keeping.
"This year could be very different with a giant cheque in your hand so turn out your drawers and check trouser pockets - the ticket could be hiding anywhere.
"Another two millionaires are guaranteed to be made every week so don't worry if it isn't your ticket as there are plenty more chances to win in every EuroMillions draw each Tuesday and Friday."
Anyone who believes they have the winning ticket for any of the National Lottery draws within the 180-day deadline should call the National Lottery Line on 0845 910 0000.
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The map was commissioned to mark Tuesday night's EuroMillions roll-over which is now a staggering £138 million - the fifth biggest jackpot ever offered in the UK.
Should anyone scoop the jackpot, their wealth will be slightly less than Europe's biggest Lottery winners Colin and Chris Weir, from Largs in Ayrshire. The husband and wife made the headlines in July when they won £161,653,000, thanks to several rollovers.
Boasting 164 National Lottery millionaires, one in 14,211 North East residents has now banked a seven-figure jackpot prize. Winners Paul and Christine Goldie from Washington, near Sunderland, pocketed £3,581,481 after their numbers came up on Christmas Day last year.
The Millionaire Map, which includes both publicity and non-publicity winners, is based on the number of millionaires created per adult population. One man who did go public with his winnings was Wayne Hughes from Holyhead on Anglesey, north Wales. The shop worker scooped £1,117,779 last August and even had the winning numbers tattooed on his arm.
The region with the fewest millionaire jackpot winners was Northern Ireland, where only 53 seven-figure or more winners were created.
Wales has seen 179 millionaires - one person in 14,502 - created over the last 16 years. Rugby fans Terry Roberts, Mike Williams, Lance Gifford and Gerwyn Jones, from the Rhondda Valley in south Wales, split £4,091,609 in April this year.