Ladbrokes, the bookmaker, has refused to pay out an accumulator bet worth £7.1 million to a man who wagered snow would fall on Christmas Day because it was accepted by mistake.
Cliff Bryant, 52, from Southampton, placed two £5 accumulators on snow falling across 24 towns and cities in the North and Midlands on December 25.
But staff at the bookmakers accepted the gamble by mistake as the company rules state such a wager can only be a single bet.
The company has honoured the relevant single bets and paid out only £31.78 instead. It has apologised to Mr Bryant for the mistake.
It is claimed the first accumulator would have netted Mr Bryant just over £4.9 million and the second £2.23 million.
The graphic designer is now seeking legal advice over the error and said he was ''gutted'' at the decision.
''This is a genuine mistake and if I make a mistake in my work like that it costs me dearly and I think the offer should be a lot more generous than they have made,'' he said.
''They are one of the leading bookmakers in the country and I think they ought to do their homework a bit better in future.''
He urged the company to make its rules clearer.
A spokesman for Ladbrokes said company rules state that ''snow at Christmas'' bets must be singles only, rather than accumulators.
''We have apologised to the customer for any confusion and for mistakenly accepting an accumulator bet when our own rules state that only single bets are available on a market of this nature,'' he explained.
''We are happy to void the bets and to pay the customer his winnings on the relevant singles.''
Independent Betting Adjudication Service spokesman Danny Cracknell said Mr Bryant had contacted them over the issue and they would investigate when he sends them the relevant paperwork.
Under the Gambling Act 2005 a bet is now an enforceable contract and Section 334 repealed the old provisions preventing enforcement.
However, Section 335 of the Act, relating to the enforceability of gambling contracts, states ''...gambling contracts may be void on the same basis as any other contract (for example, on the basis of lack of intention, mistake or illegality)''.
Few gamblers are aware of this but most bookmakers have a rule in their small print which says that multiple bets on events which take place less than 15 mins apart are null and void. They do not normally enforce this rule unless the payout is for a very large amount.
