Mr Byrne was shot dead in the Regency Hotel during a boxing weigh-in in the north of the city in February.
This is the second search to be carried out in a week.
RTÉ has reported that searches are being carried out on ten houses and flats in Dublin's south inner city.
The operation began at around 06:30 local time on Friday morning.
It is understood that over 80 armed gardaí are involved in the investigation, as well as the Emergency Response Unit, the Drugs and Organised Crime unit and the Criminal Asset Bureau.
On Wednesday, Irish authorities seized over 1m euros (£770,000) worth of luxury cars, cash and other valuables.
Irish police have begun another series of raids on properties linked to members of a criminal gang connected to shooting victim David Byrne in Dublin.