The National Lottery has urged players to check their tickets in case they are one of four missing millionaire winners.
The players each won £1 million in the EuroMillions Millionaire Raffle draw on November 12 but have yet to claim their prize, a National Lottery spokesman said.
The winning tickets were bought in Blackburn, Stoke-on-Trent, the London Borough of Ealing and the Arun District Council area of West Sussex.
The ticket-holders have until 5.30pm on May 11 to make their claim.
The special draw gave away 10 £1 million prizes. Six winners have already claimed their prize.
The spokesman said: "There are four secret millionaires hidden across the country and all they need to do to claim is check their numbers and give us a call.
"We want players to check down the back of the sofa and in coat pockets as these millions could be hiding anywhere.
"Another millionaire will be made this week so don't worry if it isn't your ticket as there are plenty more chances to win each and every Friday."