A police officer has been arrested on suspicion of perverting the course of justice following allegations over inaccuracies in crime reports.
Officers from the Metropolitan Police's directorate of professional standards arrested the detective constable from Sapphire Command, a specialist sexual offences unit, on Friday morning.
He is being held in custody while two properties are searched and pending further investigations.
An investigation was launched in May after senior managers in the force became aware there may have been inaccuracies in some of his crime reports.
The officer was suspended on May 18 and due to "recent significant developments" the decision was taken to arrest him, a spokesman said.
The Independent Police Complaints Commission is carrying out an independent investigation.
The officer works for the sapphire unit responsible for the Camden and Islington areas of north London and 26 live investigations and 37 closed cases are being reviewed as a result of the inquiry.
All live investigations have been assigned to new officers.
The spokesman added: "As the investigations are reviewed, if there are any issues identified that may alter the course of the investigation the victims are being contacted - so far we have contacted two victims about their investigations."
Anyone with concerns about how their investigation has been handled should contact the sapphire unit on 020 7421 0282.