Lottery operator Camelot says that the £64 million win would be the largest ever to go unclaimed.
Hertfordshire residents are being urged to check their pockets, cars and sofas for the missing ticket.
Click here for the full interview.
More top news
Londoners who have received new electronic gadgets for Christmas are being advised to take simple steps to protect them from thieves.
The Boxing Day sales got off to a flying start with shops reporting a surge in business during the first hour of trading.
Bus strikes are planned for Monday 29 December and Monday 5 January.