A police officer today admitted sabotaging investigations into rapes and sex attacks across London.
As a a result 11 suspected sex attackers will not be charged, a court heard today.
DC Ryan Coleman-Farrow, 30, told senior officers that rape victims had dropped the allegations while informing the traumatised women that their cases were being shelved.
Coleman-Farrow had not bothered to interview key witnesses, failed to look for CCTV of the sex attacks or follow up forensic clues in 13 cases involving 12 victims.
In each case he falsified police records to cover up the lies he told working on Scotland Yard's Sapphire Unit - the specialist team which investigates rapes and sex attacks.
His actions meant several cases were "incapable of full and proper investigation" and will always remain unsolved. Coleman-Farrow appeared in the dock today at Southwark Crown Court and spoke only to confirm his name and register his guilty pleas.
All the offences were committed between January 2007 and September 2010 while he was based at Kingston upon Thames.
Prosecutor Mark Heywood QC said: "The case involves investigations by this defendant, a serving police officer, into allegations of sexual offending.
"The indictment alleges against him 13 offences of misconduct in relation to each of the 13 investigations carried out by the Met in which he took part.
"Behind the evidence stand 12 complainants and 11 suspects in total.
"In almost all cases no proceedings resulted and certainly no conclusion adverse to anyone was ever reached."
He added: "The Crown's case is the conduct complained of has led to a point where in some cases it was incapable of full and proper investigation."
In one case, between August 1, 2009 and February 1, 2010, the officer said he had spoken to the rape victim and she had withdrawn her support from the investigation.
Coleman-Farrow also failed to submit evidence for forensic analysis and before faking records to pretend forensic examinations had failed, between 5 January 2010 and 1 June 2010.
He further falsified police records and witness statements to cover his tracks, and in five cases he lied to victims saying the Crown Prosecution Service had dropped the charges.
Coleman-Farrow was sacked by the Met in April 21 last year after an internal investigation. At the time Cleman-Farrow was suffering from testicular cancer.
The court heard he was "not looked after as well as he could have been" by the Met but it is understood that this was not his primary motivation.
The former officer, of St Leonards on Sea, East Sussex, admitted 13 charges of misconduct in a public office.
J Judge Alistair McCreath bailed Coleman-Farrow ahead of sentencing on Ocotber 11.
