A family have finally cashed in their winning bet on a famed Grand National race nearly half a century on.

Bob Holmes, 76, discovered a slip for the £1 stake on Red Rum's historic romp to victory in the 1974 race, one of a still unmatched trio of wins by a single horse.

The bet was placed by his Mr Holmes' father-in-law Joe Robertson, who never went back to claim his winnings of £12.

The family discovered the still-uncashed slip from bookmakers William Hill as they were clearing out Mr Robertson's belongings long after his death in 1978 at age 85.

Mr Holmes and his wife Nancy, 75, approached the betting firm, which offered to pay out the stake with adjustment for inflation.

It means that the family took home winnings of £130 - and they were also given a matching sum in free bets.

They plan to lay a stake on this year's race in tribute.

Mr Holmes said he spotted an old betting slip while going through his relative's old papers that "piqued his curiosity" as it related to the historic race.

He speculated that his father-in-law must have searched all over the house for the winning slip.

He added: "I think he must have lost it - then turned the house upside down looking for it.

"It's good fun. We've divided the winnings evenly among the three of us and hopefully we'll have some more money."

He added that he will not be repeating his father-in-law's mistake if his horse wins at this year's race.

"If my free bet comes in then I'll be taking my winnings immediately," he said.

"There's been no paper exchanged for this so I have nothing for my children to find in 40 years."

William Hill said the stake was by far the longest-uncollected winnings they had ever dealt with.

Spokesman Graham Sharpe said: "It's difficult to understand how someone who backed Red Rum would not have collected their bet as anyone who did usually boasts quite a bit about backing the Grand National winner.

"Our previous record for an uncollected bet was in the 1970s when a woman only felt able to go through her late husband's clothes after seven years and found a slip in his suit pocket.

"But Bob's win smashes that by quite a distance.

"What I remember about Red Rum was that he would regularly take us to the cleaners in the 1970s and here he is more than 40 years on still doing it."

Mr Holmes plans to bet on Blaklion at £20 each way on this year's Grand national, which culminates tomorrow.

In an homage to Red Rum, his wife has backed Definitely Red at £25 each way while her sister Rhoda has backed Ucello Conti at £20 each way.

The original bet had been traced back to a William Hill branch in Paisley which now no longer exists.