At least 40 motorists convicted of drug-driving offences have been cleared after evidence of manipulation was found in the forensic testing process.
The motorists were banned from driving and in some cases fined, but their convictions have since been overturned.
About 10,500 test results are being reviewed after data was allegedly manipulated at Randox Testing Services.
The National Police Chiefs’ Council (NPCC) described it as a « most serious breach » of forensic science standards.
Delays in re-testing
A further 50 drug-driving cases have been dropped as a result of the alleged data manipulation at the firm’s Manchester office.
Police suspended all contracts with the company in November last year.
Greater Manchester Police has arrested two men, aged 47 and 31, who work at one of the company’s laboratories.
They were arrested on suspicion of perverting the course of justice.
Another man has also been interviewed under caution as part of what the Justice Minister, Lucy Frazier, described last month as an « expansive » criminal inquiry.
As a result of re-testing, two drug-driving cases that resulted in road deaths were referred to the Court of Appeal.
Both convictions were upheld but one motorist’s sentence was reduced.
Two other cases involving drug-driving have also been sent to the Court of Appeal. One conviction was quashed and the other has yet to be decided.
Ch Con James Vaughan, NPCC lead on forensics, said he could not remember a forensic science failure « of this magnitude ».
He said re-testing was taking longer than expected because there was a « chronic shortage » of scientific expertise and accredited laboratories, leading to delays in providing toxicology analysis in unrelated cases of sexual offence and rape.
Source: The Guardian