One hundred lucky ticketholders became millionaires in a special EuroMillions Millionaire Raffle draw to mark the Olympics opening ceremony last night.
However 65 people still don't know of their good fortune as only 35 new millionaires have come forward to claim their prize so far.
A spokesman said: "The 35 new millionaires will have woken up feeling like they have struck gold this morning.
"They will never forget July 27 - not only was it the opening night of the Olympic Games but also the night they became a millionaire.
"We urge all EuroMillions players to check their tickets as there are 65 further £1 million prizes to be claimed.
"In addition to creating so many overnight millionaires, this special draw has helped boost the £30 million-plus raised for National Lottery Good Causes by players every week."
Players can check to see whether they are a millionaire by going to www.national-lottery.co.uk or visiting any National Lottery retailer.