Sgt Murphy said it was a complex investigation taking place in Ireland and in Croatia and allegedly involving €2.1 million worth of drugs.
Judge Mary Dorgan added that the DPP might decide on a court higher than the circuit court.
Det Garda Ryan Dillon previously objected to bail in the case citing the strength of evidence and the seriousness of the charges facing the accused.
He said that Mr Slivar made no reply after each charge was put to him under caution.