The note that arrived at the Department of Agriculture didn't beat around the bush. It said, "This is a demand for £5 million". If the demand was not met, the note went on, its authors would unleash a potentially catastrophic outbreak of foot and mouth disease.

If this sounds like the start of a pitch for a new Netflix thriller – and it sort of does – it’s much more intriguing than that, because it’s true. It happened in 1976. And we’re only getting to hear about it now thanks to intrepid investigative journalist and former RTÉ stalwart, Charlie Bird.

Charlie Bird revealed the astounding story to Joe Duffy

Charlie told Joe Duffy on Liveline how he got the ransom demand story from former fraud squad detective and Mayo footballer, Wille "Four Goals" McGee, while researching for material for a podcast series he was doing for The Senior Times:

"He gave me this story and Joe, you are right, it is the most incredible, remarkable story. It’s just unbelievable."

Unbelievable is the word. And yet it actually happened. The story begins with the typewritten letter sent to the Dept of Agriculture in late August 1979 and it goes from there over a six-month period to the personal ads in the Irish Times, a secret phone line, a British-registered Mini Cooper and an armed male garda dressed as a woman riding a bike back and forth across a bridge. To repeat: this actually happened.

"They were threatening to spread foot and mouth disease around this country. They said they had the wherewithal to do it and they were threatening to do that."

There was an outbreak of foot and mouth in 2001, which, Charlie tells Joe, cost the country half a billion euro. It led to border checks, the cancellation of the St Patrick’s Day parade and GAA matches being postponed. Sound familiar?

"In a way, Joe, this story has a resonance for the Russian cyberhackers and the pandemic. So, what these people were threatening to do was to basically spread a pandemic around the country."

The ransom demand letter contained instructions on how to communicate with the criminals via coded messages in the personal ad column of the Irish Times.

The 2001 outbreak of foot and mouth disease led to closures across the country

"At one point, people in the Irish Times got suspicious of what the hell was going on and they contacted the bosses of the Fraud Squad to see if these ads were legitimate, if they were real."

Eventually, the gardaí were told to obtain a white Mini 1000 with English plates, put a suitcase with £5 million in it on the passenger seat and drive a prescribed route from Dublin to Waterford and back again. And it was on that journey that the gardaí believed the criminals would make a grab for the suitcase.

The Garda Fraud Squad, several armed officers, both in and out of disguise, and two naval vessels were involved in what it was hoped would be the operation to catch those demanding the ransom red-handed.

"Four-Goals Wille had a gun and he said that at one point he thought that there might be a shoot-out and he said he was shaking and he couldn’t even take the gun out."

You can hear Joe and Charlie’s full conversation about this remarkable ransom demand story by going here.