New advances in the technology mean detectives will know if an offender is black or white, the colour of their hair and eyes, their height and age – even if there are no witnesses to the crime.

Until now, investigators have only been able to match genetic material to records of criminals already in the national database, but the innovation will produce a ‘DNA photofit’ describing the offender.

Dr Denise Syndercombe-Court, a forensic genetics expert at King’s College London, said: ‘The new technologies raise the possibility that we won’t need an actual eyewitness to a crime in order to produce a picture of how the suspect looks.