The Director of Public Prosecutions is understood to have decided to proceed with a criminal prosecution against a member of the Garda accused of trying to prevent a doctor taking a blood or urine sample from a businessman.
The Co Louth businessman had been arrested on suspicion of drink-driving and was taken to Dundalk Garda station.
A superintendent from another area investigated and forwarded the file to the DPP. The case is expected before the District Court early in the new year.
The doctor was en route from Slane to Dundalk Garda station when, it is alleged, two gardai stopped his car and told him to go home. However, another garda ensured he reached the station and took the sample within the specified time.