An “urgent” review into the Metropolitan Police is taking place after it was revealed that 33 criminal investigations may have been affected by suspected forensics mishandling, Scotland Yard has confirmed.

The Directorate of Professional Standards is investigating after a forensic scientist working within the Met’s Forensic Services allegedly mishandled  material in its laboratory.

More than half of the cases – 21 out of 33 – relate to investigations into rapes and other sexual assaults, while 12 are investigations into violence, burglary and drugs offences, the Met said.

It said the scientist allegedly “did not complete the requisite forensic examinations and in some case wrongly informed investigators about the progress of forensic examinations.”

The scientist was suspended on 26 March as part of the investigation.

The Met said in a press release: “An internal review has found that 33 separate criminal investigations have been affected.  The cases relate to crimes whereby items were submitted for forensic examination between 2012 and 2017.

“We are urgently conducting a review to understand whether there is any risk to the criminal justice process and to take remedial action where necessary.

“All victims in the affected cases have been contacted, where it has been deemed appropriate to do so.”

It added that in the rape and sexual assault investigations, victims have been contacted by a Sexual Offences Investigative Techniques officer.

The force said it has completed a “full audit” of all its forensic scientists’ workloads “in order to be reassured that this issue is not more far-reaching”.

It said it was “satisfied that there are no other instances of undeclared casework.”

The case has also been referred to the Forensic Science Regulator.