The money has been donated to the National Lottery Good Causes
A jackpot of more than £3.6m has been donated to the National Lottery's charity fund after the ticket holder failed to claim the prize.
The ticket for the main Lotto draw held on 23 September 2009 was bought in the Highlands, and had the winning numbers 23, 25, 28, 41, 46 and 47.
The National Lottery had previously said the holder had until 1730 GMT to claim the prize.
But the £3,681,197 prize remained unclaimed 180 days after the draw.
The ticket was bought in the constituency of Inverness, Nairn, Badenoch and Strathspey.
Camelot Group, operator of the lottery, has confirmed that the money, plus the interest it has earned, has now passed over to the National Lottery Good Causes.
A National Lottery spokeswoman said: "Unfortunately, I can confirm that the ticket-holder did not come forward within the deadline to claim their prize and has now sadly missed out on this substantial amount of money.
"We tried very hard to find the ticket-holder and it's a real shame that they have missed out, but there is still one winner - the nation."