Two employees of Randox Testing Services arrested, with 484 police inquiries based on toxicology results under review

This article is more than 3 years old

This article is more than 3 years old

Hundreds of drug tests may have been manipulated by staff at a forensics lab, with almost 500 police investigations under review.

Two employees of Randox Testing Services (RTS), which analyses blood, saliva and hair samples on behalf of police forces, have been arrested by Greater Manchester police.

RTS said the issue had come to light as a result of an internal investigation at its Manchester site.

The National Police Chiefs’ Council’s forensic science lead, Ch Const Debbie Simpson, confirmed a criminal inquiry had started into the “quality failure” and that 484 cases would need to be reviewed.

Forces around the country would now determine “if compromised data played a part in prosecution, and the CPS will then take appropriate action”, she said.

It raises the possibility that hundreds of people could have been the victims of miscarriages of justice because of convictions based on incorrect toxicology test results in their cases.

RTS said the manipulation was of quality control data supporting the test results, rather than the samples themselves. It said no alcohol samples were affected, and some tests could be “rerun to provide robust, uncompromised results”.

The government closed down the independent state-run Forensic Science Service in 2012 amid multimillion-pound annual losses. Forensic testing is now either done in-house by police forces or outsourced to private companies.

Last month the official regulator Dr Gillian Tully told the Guardian that further cuts to the forensic science budget would compromise quality and damage the British justice system.

RTS, based in Northern Ireland with offices in London and Manchester, says on its website that it is “a world leader in clinical diagnostic solutions with offices and distribution in over 145 countries”.

It is part of the Randox Laboratories group, which includes Randox Health, the sponsor of UK horse racing’s premier event, the Grand National.

RTS’s website adds that it is “entrusted by the majority of UK police forces to provide forensic toxicology testing”.

In a statement on the website, it said the investigation was limited to its Manchester site.

GMP said two men aged 47 and 31 had been arrested on suspicion of perverting the course of justice and bailed until next month.

A GMP spokeswoman confirmed it had been asked to investigate forensic results issued by Randox Testing Services.

She added: “Randox Testing Services have provided forensic services to police forces, including GMP, for the past two years. The organisation is being fully cooperative [with] the investigation.”