Retesting is underway into more than 10,000 criminal cases of alleged data manipulation linked to a Manchester laboratory owned by Co Antrim company Randox.
However, none of those cases are linked to any ongoing PSNI investigations, a spokesperson confirmed last night.
The National Police Chiefs' Council said yesterday three-quarters of the cases to be retested, across 42 police forces, were traffic offences such as drug driving, with the rest including violent crime, sexual offences and unexplained deaths.
Retests have so far found no impact on cases of sexual offence, violence or homicide.
But a number of retests had resulted in drug driving cases being discontinued and two road deaths had been referred to the Court of Appeal.
Two men have been arrested and three 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 manipulation emerged earlier this year when a data anomaly in a drug driving case was reported to Randox.
The company, with headquarters at Diamond Road in Crumlin, Co Antrim, said it reported the anomaly to police.
"In early 2017, the forensic testing company RTS became a whistle-blower when it exposed evidence of alleged data manipulation. Almost one year on, it remains committed to ensuring the police investigation will succeed in bringing those responsible to justice and protecting the criminal justice system".
The company has partially suspended criminal forensic testing while the retests take place.
RTS Toxicology Manager Dr Mark Piper said: "We have acted as whistle-blower to ensure the integrity of the criminal justice system. We will continue to work with Greater Manchester Police and the appropriate authorities in the investigation. We will do all that we can to ensure this situation is resolved and deeply regret the distress that has been caused.
"We are now well-advanced in developing a fool-proof testing system which would enhance the security of our operations in the future, to provide the necessary level of confidence," Mr Piper added.
Around 50 cases due to go to trial in England have been dropped as a result of the investigation, some were discontinued due to there being no sample available for retesting.
Potential data manipulation at a separate facility, Trimega Laboratories, is also being investigated by Greater Manchester Police.
This may affect child protection and family court cases, two further suspects arrested in connection with the alleged malpractice work for Trimega. Again no Northern Ireland family court cases are included.
Gillian Tully, of the Forensic Services Regulator, said all major forensic toxicology suppliers had been asked to carry out a detailed audit of a sample of their cases to ensure the issue was not more widespread.
She said: "If there was large-scale manipulation going on across the board I do expect it would have been found during that audit".
PSNI Chief Superintendent John McCaughan, of the Legacy and Justice Branch said the force has not used Randox for crime related toxicology services.
"Therefore, none of the cases that have been identified as having been processed by Randox relate to any PSNI investigations”.
Mr McCaughan added that the "PSNI has full confidence in the toxicology services provided by Forensic Science NI (FSNI)"
"Forensic Science NI currently broker out some PSNI cases to another toxicology provider based in England".
However said they are confident that this provider is fully compliant with regulation processes and there is no risk of similar data manipulation.
