MORE than 380 Lancashire police cases hang in the balance after a national scandal over data manipulation at a forensic lab.

The force said the majority are drug and alcohol-related driving offences spanning back to 2013 and the force has stressed that re-testing may take several years.

It comes after scores of prosecutions nationally have been dropped and several convictions hang in the balance after 10,000 potential cases of data manipulation were identified at a forensics lab.

The National Police Chiefs’ Council said forensic tests across 42 police forces, including rapes and murders, were being considered possibly unreliable and needed re-examining.

Three quarters of the cases were traffic offences such as drug driving with the rest including violent crime, sexual offences and unexplained deaths, spanning back to 2013.

Toxicology tests are carried out to detect the presence of drugs or alcohol in someone’s hair, blood or urine and can be relied on as evidence in court.

As a result of the breach in standards, around 50 drug driving investigations have been discontinued, while two road death convictions have been referred to the Court of Appeal.

Retests have so far found no impact on cases of sexual offence cases, violence or murder, the NPCC said.

The Forensic Science Regulator said in terms of numbers of cases, it was the biggest issue of its kind ever to happen in the UK.

Two men have been arrested and five interviewed under caution by Greater Manchester Police over the alleged manipulation by individuals working at a Randox Testing Services (RTS) site in Manchester. The alleged misconduct emerged earlier this year when a data anomaly in a drug driving case was reported to RTS.

A police spokesman said: “Initially we were informed that only cases dating from December 2015 onwards were affected, but since the investigation this has extended to cases dating back to 2012.

“We have a total of 389 affected cases. The majority of these cases are RTA drug and alcohol related driving offences.

“There is a National strategy for re-testing these affected samples.  Due to the numbers involved and the limited capacity within the remaining Forensic Service Providers, the re-testing may take several years.”