David and Lynn Bryant’s “living hell”, as they call it, began four years ago with a note pushed through the letterbox of their home.

Addressed to Mr Bryant, the letter began: “Dave, its Danny Day. 35 yrs ago I used to collect the glasses in the Legion and I am the same one that you ... played darts with in the fire station (remember!) At 6 o’clock tonight, I am going to the police station to report what went on and at 7 to the national papers. I think it is time you and me had a chat.”

The letter, obtained by The Telegraph, concluded: “One way or another you will pay for what you done.”

The two scribbled pages would lead to a miscarriage of justice and the jailing of Mr Bryant, then aged 63, for eight and a half years for raping a schoolboy.