For two friends with checkered pasts it was the luck of a lifetime: a 4 million-pound ($5.2 million) lottery win.

But Mark Goodram and Jon-Ross Watson may see their celebrations cut short.

The Sun newspaper reports that Britain's National Lottery is withholding the payout as it investigates whether the men, who have a string of criminal convictions, used illicit means to buy the winning ticket.

The Sun said neither man has a bank account, leading lottery organizers to investigate how they obtained the bank-issued debit card that paid for the 10 pound ($13) scratch card.

Camelot, which runs the lottery, said Friday it couldn't confirm details of the story because of winner-anonymity rules. The firm said it holds a "thorough investigation" if there is any doubt about a claim.