More than 40 people have had criminal convictions quashed following an investigation into alleged data tampering at a forensics lab, the National Police Chiefs' Council (NPCC) said.

The NPCC's forensics lead, Chief Constable James Vaughan, said on Thursday that more than 50 drug-driving investigations were dropped, with some 2,700 results re-analysed so far.

A further 41 drug-driving cases which had already resulted in convictions or guilty pleas have since been reopened and overturned, he added.

The retesting of more than 10,500 cases opened since 2014 came after allegations emerged that scientists at a Randox Testing Services (RTS) site in Manchester had manipulated forensics data.