Red Rum
Red Rum won the Grand National in 1973, 1974 and 1977 Evening Standard/Getty Images

A family have cashed in on a winning bet from the Grand National – 43 years after the race finished. Bob Holmes found the £1 bet while going through his late father-in-law's paperwork.

The bet was on Red Rum winning the 1974 Grand National – which he did. The horse had won the 1973 Grand National from 30 lengths behind and it is often considered one of the greatest Grand Nationals in history. Red Rum achieved an unmatched historic treble when he won the Grand National in 1977 and came second in 1975 and 1976.

Through a shop code, William Hill found that the 1974 bet had been placed at odds of 11-1, meaning a pay-out of £12.

But the firm decided to add inflation, increasing the pay-out by more than ten times to £130. They also gave out £130 in bets and donated £130 to Water Aid.

Bob Holmes, 76, his wife Nancy, 75, and Nancy's sister, Rhoda Robertson, 79, all from Houston in Renfrewshire, are sharing the winnings and have each placed bets on Saturday's Grand National.

The £1 bet had been placed by Mr Holmes father-in-law Joe Robertson, who died in 1979 at the aged of 82.

The family made the discovery while Mr Holmes was helping his sister-in-law move house.

Speaking to the BBC, Ms Robertson said she had been planning to throw all her father's old paperwork out. "But I'm quite a curious person so started looking through it and saw the betting slip with Red Rum on it," she said.

"I thought I could keep it as a curiosity but thought it might be worth letting William Hill know. I was very surprised when they said they would pay out and delighted when they said they would inflation-proof it."

William Hill spokesman Graham Sharpe said: "Everyone has heard of Red Rum so it's difficult to understand how he didn't collect his winnings.

"I've been with the company for 45 years and we always go out of our way to settle any late claims – but the previous record was seven years.

Taunton Races
William Hill surprised the family buy paying out with inflation Alan Crowhurst/Getty Images

"We ascertained that the code referred to a shop that is no longer a betting shop but proved it was genuine. It seemed a bit churlish to just pay out £12 so we agreed to add inflation which made it £130.

"We also donated £130 to Bob's chosen charity Water Aid and gave out an additional £130 worth of bets for this year's Grand National to see if the family luck would maintain itself over 43 years."

Red Rum died on 18 October 1995, aged 30. His death made the front pages of national newspapers.