Police corruption was rife in the case of the Cardiff Three,in which the murder of a prostitute took place in 1988. I think it was about 9 officers who were charged with corruption in that case.
Similar to Jeremys',,,,, hidden documents/files. Paperwork which was told it had been destroyed,,,and wasn't.
Two of the innocent men who were charged with murder have since died. I doubt they ever got a pardon,,as the excuse is,when it comes to releasing those who've suffered an injustice,are usually released " on licence " !.