The 180-day deadline to pick up the cash has expired, meaning Camelot to donate the cash pool to its Good Causes Fund.

The lottery operator said there was a further £36 million still within the deadline, but that would be added to the fund unless winners staked their claim soon.

Camelot believes that most of the prizes which go unclaimed are £10 wins which are lost when people do not check their tickets carefully enough.

"Then again people could have lost them or just forgotten where they are. Whatever the reasons, £150 million worth of prizes could have made a lot of people happy," a Camelot spokesperson said.

The jackpot winning ticket was bought in Hull for a draw in May 1996 but despite a massive hunt for the winner, no one came forward.

The second biggest prize which could go unclaimed was also won by a ticket bought in Hull.