A city is bracing itself for a frenzy of back-of-the-sofa searching and sock drawer ransacking after details were revealed of an unclaimed £5 million lottery prize.

National Lottery operator Camelot said the £4,908,817 Lotto jackpot from Saturday August 29 was won by a ticket bought in the Sheffield area, but no one has so far come forward to claim the prize.

Now the search is on to trace the would-be millionaire.

A press officer for Camelot said the draw was made during the Bank Holiday weekend and, therefore, there's a chance the winner was visiting the Yorkshire city during the break.

The lucky ticket-holder has until 5.30 p.m. on Thursday February 25 next year to make their claim. The winning Lotto numbers were 9, 18, 34, 37, 39 and 47.

If no one comes forward with the winning ticket before this deadline, the prize money plus all the interest it has generated will go to the Good Causes.

The biggest ever unclaimed jackpot was one of £9.4 million. The unlucky punter in that case bought their ticket in the Doncaster area of South Yorkshire in 2005 but never came forward to claim the cash.

The Camelot press officer said: "We're desperate to find this mystery ticket-holder and unite them with their winnings - this amazing jackpot prize could really make a difference to somebody's life. We're urging everyone to check their old tickets again or look anywhere a missing ticket could be hiding."

Anyone who believes they have the winning ticket should call the National Lottery Line on 0845 910 0000.