A helmet and a lifejacket, believed to be from the doomed Rescue 116 aircraft, have washed ashore in Elly Bay, near Clogher, Co. Mayo.
A walker spotted the items on the shore early on Saturday morning and alerted authorities.
Rescue 116 crashed on a slope in Blackrock Island on March 14 last, killing all four crewmembers on board.
The bodies of winchmen Ciaran Smith and Paul Ormsby remain missing.