Garda Commissioner Martin Callinan says An Garda Síochána has co-operated fully with the Ombudsman's investigation into the case of Kieran Boylan.
Mr Boylan is a convicted drug trafficker, who had faced charges that were dropped in 2008.
The Garda Ombudsman Commission's investigation has so far taken more than four years but is expected to be completed in the next few weeks.
Mr Callinan said he has fully facilitated the Ombudsman Commission and nothing has been done to inhibit the investigation.
The Commissioner also said it was for the Ombudsman to send material to the Director of Public Prosecutions and for her to decide if any prosecutions linked to the Boylan case were found to be unsound.
He said he would await the outcome of her deliberations.
The Commissioner was speaking at the presentation of Scott Medals for bravery to seven members of the gardaí at the Garda College in Templemore.
The gardaí were honoured for exceptional courage and bravery in the course of their duty.
Five faced down gunmen even though weapons were pointed at them and they were threatened they would be shot.
The other two went into a burning house in Co Wexford and rescued a woman and two children, aged two and three, from an upstairs bedroom.