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
Services on major rail routes between London and south west England have been severely disrupted after a person was hit by a train.
The business executive, whose ruthless interviewing technique has won him many fans, is replacing Nick Hewer, who quit after a decade.
Recent opinion polls show Labour within striking distance of capturing the trophy seat of Finchley and Golders Green.