A GROUND-BREAKING police bugging operation helped to trap one killer and implicate a second.

Police covertly filmed a prison visit between Teresa Wilkinson and boyfriend Mark Graham, who was being held at Holme House Prison, Stockton, charged with his part in Mr Sharif's murder.

Graham was caught on an audio tape referring to the "loads of times" Mr Sharif had been hit, including in the throat and head; while also saying "all I did is just hit him and he died" together with "it's not murder, it's manslaughter".

Detective Superintendent Adrian Roberts said: "The audio tape was to be a ground-breaking and pivotal piece of prosecution evidence at trial, it being the first time such material has been used in a British court."

When questioned by detectives, Graham had also denied any association with Embleton who, because of insufficient evidence, was released pending further inquiries.

Film footage, shot by the hidden camera in Holme House Prison, was enhanced and lip- read by an expert, suggesting Graham did know Embleton.

Unable to deny the evidence of the tapes, Graham tried to escape a life sentence for murder by entering a guilty plea to the lesser offence of manslaughter - but to no avail.

Other evidence came from forensic tests which found fibres from Mr Sharif's pullover on Graham, Ham and Embleton's clothing and in Graham and Ham's flats in Stamford Street, Middlesbrough