More than a dozen police forces have outsourced digital forensic investigation work to unaccredited private laboratories in the past year.

At a time when a number of rape cases have had to be abandoned due to problems with digital evidence, this is concerning news.

Fresh concerns have now emerged regarding the quality of digital forensic evidence being used to support the prosecution in serious crimes, including rape and child abuse.

At least 15 police forces have outsourced digital forensics work such as the analysis of mobile phones and computers to unaccredited private companies, some of which aren’t expected to abide by any regulations.

One private company connected to a number of forces had its accreditation revoked last year after failing an audit. However, it continued to carry out forensic work for the prosecution.

Last year, the government set an October deadline for police forces to improve standards within their in-house laboratories. In particular, forces were asked to abide by minimum quality standards for analysing mobile phone, computer and CCTV data. Just 15 out of 43 police forces met this deadline.

Nick Baker, the national police lead on digital forensics and deputy chief constable of Staffordshire police said that problems have arisen due to the sheer scale of digital evidence that the police are faced with.

With so many mobile phone and computer records to go through, teamed with funding shortages, some forces are struggling to comply with quality standards.

He said: “The speed at which that’s come upon us is immense.”

Gillian Tully, the government’s forensic science regulator said there is “no excuse” for forces to use unaccredited providers. She added: “It is clearly of concern when contracts are being placed with providers that are not compliant.”

In some cases, police forces are outsourcing digital forensics work to one private company, only for that company to subcontract casework to other private firms.

According to an investigation by The Guardian, one analyst at a private digital forensics company said that text messages and images are sometimes “cherry-picked” by the prosecution and efforts are made to encourage the defendant to plead guilty.

Digital forensics was once an optional element of an investigation but over the years it has evolved to become an essential line of enquiry in almost every investigation. Messages, photographs and internet searches can help police forces and prosecutors gain an insight into what may have happened.

However, there have been instances where this data has been manipulated. For example, 26-year-old Danny Kay’s conviction was recently overturned after new Facebook messages came to light suggesting sex with his accuser was consensual.

Digital evidence isn’t the only area that police forces are falling short. According to Gillian Tully, approximately half of all forces are set to miss a 2018 deadline for complying with fingerprint analysis standards.