A detective has been forced to resign over her responsibility for "poorly handled" covert surveillance in a probe into the disappearance of a 14-year-old girl.
Det Sgt Jan Beasant had fallen "well short" of expected professional standards and showed conduct that "lets everyone down", Lancashire Constabulary said in a damning indictment.
She had the job of transcribing secretly recorded conversations between two suspects who later went on trial over the alleged murder of Blackpool teenager Charlene Downes.
She spent 2,500 hours over two years listening to 52 audio tapes of recordings from bugs placed in the car and flat of one of the men. Iyad Albattikhi, 33, was later formally cleared of Charlene's murder and Mohammed Reveshi, 54, was acquitted of helping to dispose of her body.
The prosecution claimed the takeaway owners were heard talking about Charlene's body being chopped up and that it had "gone into kebabs".
A jury at Preston Crown Court was discharged in 2007 after failing to reach a verdict in their trial and a scheduled retrial collapsed when the Crown Prosecution Service conceded it had "grave doubts" about the reliability of some of the evidence in the case. The quality of the covert recordings was criticised during the trial by defence barristers as "poor" with confidence "low" in the accuracy of the transcriptions.
John Bromley-Davenport QC, defending Mr Reveshi, said Det Sgt Beasant was totally unqualified for the task of listening to the tapes and already knew a huge amount about the case.
A review by the Independent Police Complaints Commission later concluded the investigating team were guilty of a strategic and tactical failure in the management of the audio and video material they obtained.
Proper records were not kept, material was not fully transcribed and the overall integrity of the material was not ensured. The use of untrained and inexperienced officers in the inquiry was also criticised.
Naseem Malik, IPCC Commissioner for the North West, said it was "abundantly clear" that the covert surveillance was "handled poorly and unprofessionally".