The chief constable told a Tory MP — who confided the revelation to an Irish diplomat, who in turn told the Irish Government — that police added “jam to the cake” to make the evidence stick.
In a courier-delivered letter, marked Secret and Personal, the diplomat alerted the Taoiseach’s office in Dublin about the claim in December 1987 — weeks before judges upheld convictions against the six innocent men.
Papers released under the 30-year rule reveal Barry Porter, then Conservative MP for Wirral South in Liverpool, privately told the diplomat some of the evidence against them was the “jam on the cake”.
“I probed him hard on this and after a little while he said he would tell me something in the strictest personal confidence if I did not use it. I agreed,” the diplomat told the Taoiseach’s office.
“He said that the Chief Constable of Liverpool told him he knew that the evidence against the six was enhanced by the police.
“It was the Chief Constable who used the term ‘adding jam to the cake’.
“He said that the police were convinced that the six were guilty and wanted to ensure that the confession evidence would stick.”
He went on: “With this target in mind they set about making sure that the confession evidence was overwhelming and ‘went about’ the six in such a way as to ensure that. I asked Porter to clarify this and he confirmed that the chief constable was talking about frightening the prisoners sufficiently to get satisfactory confessions out of them.” Although Mr Porter did not name anyone, the diplomat notes that the then chief constable was Kenneth Oxford.
The diplomat suggested if an appeal against the Birmingham Six convictions failed — and it did weeks later — then “it might be considered then whether Oxford could be somehow induced to make the same comments to someone other than Porter, in such a way as to make his remarks usable by the appellants’ counsel.”
The diplomat says he did not feel he could “push Porter too hard on detail without betraying excessive interest”.
The Birminghan Six — Paddy Hill, Gerry Hunter, Johnny Walker, Hugh Callaghan, Richard McIlkenny and Billy Power — were not freed until March 1991, after their convictions for the murders of 21 people in two pub bombings were quashed.
They had served nearly 17 years behind bars in one of the worst miscarriages of justice seen in Britain.