For England fans of a certain generation, it is a game that left deep scars.

In a crunch World Cup quarter-final 56 years ago, the Three Lions fell to a 3-2 defeat against West Germany – ending any hope of retaining football's top title.

Now, as far-fetched as it may sound, it has been suggested the loss could have been part of an incredible Cold War plot hatched by the US.

Some believe foul play was at hand in relation to Gordon Banks falling ill with food poisoning hours before the clash.

The absence of the man then regarded as the world's best goalkeeper from the match in Mexico significantly harmed England's chances.

Banks had first experienced symptoms after the final group game against Czechoslovakia, but was believed to have recovered before relapsing on the day of the quarter-final.

He was replaced by Chelsea's Peter Bonetti, who many deemed at fault for all three goals. Others pointed to the substitution of Bobby Charlton in the 70th minute.

Some in football have long believed Banks – who died in 2019 aged 81 – was 'nobbled' that fateful morning in 1970.

And a three-year investigation has now looked into the claim, with a particular focus on whether the episode was part of a CIA effort to ensure eventual victors Brazil won.

Gabriel Gatehouse, the former international editor of BBC's Newsnight, began working on the story after being contacted by Banks's grandson, Ed Jervis. In his autobiography, Banks appeared to blame a bottle of beer for his illness.

But Mr Jervis told the journalist his grandfather was 'always vaguely suspicious', while the goalkeeper's son, Robert, added: 'He thought it was damned odd that only he got ill, and very seriously ill.'

It comes after legendary late football journalist Brian Glanville wrote in his 2007 book England Managers: The Toughest Job In Football that 'I have steadily come to believe that Banks was the victim of sabotage'.

According to Mr Glanville, another football writer named Bob Oxby told him he had a cousin, Stuart Symington, who was senator for Missouri from 1952 to 1976. 

On Banks's illness, Mr Symington allegedly told Mr Oxby: 'That was the CIA. You don't think we were going to let England beat Brazil, do you?'

The US supposedly intervened to help prop up a military dictatorship which Lyndon Johnson's administration helped to install in 1964.

By the time of the World Cup six years later, the regime was unpopular and winning the tournament was seen as a good way to boost support.

Mr Gatehouse spoke to Mr Glanville about the story two years before his death last year at the age of 93.

'All he would say was that Oxby was a reliable reporter, and that Symington had told him it was "part of a plan,"' Mr Gatehouse wrote in The Observer. He said Mr Symington served on the armed services committee, which received CIA briefings.

Mr Gatehouse also found a document in the agency's archive from 1971 which noted that Brazil's president, General Emilio Garrastazu Medici, 'skilfully managed to associate himself' with the victory.

But the journalist admitted his contacts in the intelligence world had not heard of any poisoning. He highlighted, however, testimony from a CIA biologist who told the senate in the Seventies of 'substances that can give you a real severe case of the "tummies"'.