A detective who was based at Kingston has admitted lying to sex assault and rape victims before dropping their cases.
DC Ryan Coleman-Farrow, 30, pleaded guilty to 13 counts of misconduct in a public office at Southwark crown court.
All the offences were committed between January 2007 and September 2010 while working with the Sapphire unit, which specialise in sexual crimes cases, and was based in Kingston.
Coleman-Farrow failed to interview key witnesses, look for CCTV or follow up forensic clues in 13 cases involving 12 victims, Southwark Crown Court heard today.
He entered false records on the police computer, advising that charges should be dropped in rape and sex attack cases, then told victims their cases had been dropped.
Coleman-Farrow was bailed ahead of sentencing on October 11.
A spokesman for the Met said: "The officer, who was based within the Sapphire Command, was dismissed from the Metropolitan Police Service on 21 April 2011 for gross misconduct following a fast track misconduct process in connection with alleged irregularities in a number of cases he was dealing with."