The Labour Party is calling on the Garda Ombudsman to formally investigate the death of Derek O'Toole in Lucan, Co Dublin, earlier this month.
The 24-year-old died in the early hours of Sunday, March 4, after being struck by a car driven by an off-duty garda.
Inquiries have established that he was lying on the road at the time, but was not the victim of a previous assault or hit-and-run.
Labour Party Senator Joanna Tuffy has written to the Garda Ombudsman seeking an investigation into the garda handling of the matter following allegations that the O'Toole family were not given all the information about the incident.