Lottery bosses may be forced to pay £2.5million to a convicted rapist who allegedly used a doctored ticket after they LOST his slip, it was reported.
Edward Putman did not face charges but Camelot were fined £3million over the 2009 scam.
See also: Camelot fined £3m after paying out on suspect lottery claim
See also: How did this woman overlook a lottery win for three weeks?
Now Camelot is looking into launching a private law suit to recoup the cash from Putman.
The group was fined £3 million last week by the Gambling Commission, which said it was "more likely than not" that the 2009 pay-out was made to a dodgy ticket.
A Camelot source said: "The Gambling Commission said it wasn't 100% proven but on the balance of probabilities, it was likely to have been a fraudulent claim.
"If that's the case and that can be proven, we'd be the victims of a fraud and we would very much like to get that money back."
A police probe into the alleged scam was dropped due to insufficient evidence.
But a source close to the investigation told the Daily Mail that one reason behind the decision was that Camelot had lost the dodgy ticket.
Legal experts claim Camelot has a higher chance of winning a case in the civil courts.
Bill Waddington, former chairman of the Criminal Law Solicitors' Association, said: "The fact that the police have decided not to bring charges doesn't prevent Camelot from taking some sort of civil action to recover the money.
"I don't know why the police decided they were satisfied there was no criminal offence they could bring, but Camelot could sue the guy on the basis that he made a dubious or fraudulent claim, as according to the Gambling Commission.
"The [standard] of proof in a criminal prosecution is 'beyond reasonable doubt'.
A civil case is based on the balance of probabilities, which means if you are 51% sure, that will do.
The Gambling Commission comment of 'more likely than not' would pass that test."But Camelot could refrain from pushing for action for fear of having its failings laid out in public, after it was claimed this weekend that Putman allegedly had the help of an inside man.
IT specialist Giles Knibbs, who worked in Camelot's fraud detection department, was alleged to have given Putman inside information that helped him scoop an unclaimed jackpot – which would have gone to good causes after 180 days.
Mr Knibbs was promised a 50-50 split of the money, sources claimed, but he and Putman fell out.
Putman, who was jailed for rape in 1993 and for benefit fraud in 2012, said he was being blackmailed by Mr Knibbs, who then killed himself before he was due in court.
Putman of Kings Langley, Herts, was arrested on suspicion of fraud but was told in February he would face no further action.
Labour MP John Mann said: "It's vital that people see that there isn't a way of scamming the Lottery. Camelot should chase the money. It's the right thing to do."
Camelot's £3million fine has already gone to good causes.
The firm said the penalty was paid by shareholders and has not left players short or hit the money it distributes.
The firm has stayed tight-lipped on the circumstances surrounding its payment on a "deliberately damaged ticket" that it no longer has.
It would not comment on this weekend's press reports as "the case may be subject to further police action".
1. Did Camelot know of a friendship between Putman and Knibbs before the pay-out?
How long afterwards did Knibbs continue to work in its fraud detection department and how did he come to leave? Sources said the pair had been acquaintances for some time before the 'win' in September 2009.
2. What is Edward Putman's side of the story?
What did he say to the police's questions? Putman was at home on Friday but refused to answer the door to reporters.
He was not seen at his house yesterday, with no signs of life inside.
3. What happened to the "deliberately damaged" 'winning' ticket?
The Mirror understands Camelot only have a photocopy, not the actual ticket, which made it difficult for the police to investigate the allegations.
4. What procedures did Camelot carry out to test the validity of Putman's claim before paying out? Did Knibbs help in that?
The stake on the £2.5m jackpot was made at the 11th hour, just before the prize was set to be handed to charities because no-one had claimed it.
5. On what basis do the Gambling Commission say it is "more than likely" the ticket was a fraud? What evidence do they have to determine that?
Allegations against Putman surfaced following Knibbs' death, with suggestions he confessed to someone before or in a note.