According to RTÉ News, the Australian manufacturer of the EPIRB devices in question was not aware of any problems until after it emerged that the beacon on the small fishing punt sailed by Paul, Kenny and Shane Bolger failed to emit a signal.
The bodies of the three men were recovered from the water in Tramore Bay just hours after they were reported missing on Wednesday 12 June.
The EPIRB - or Emergency Position Indication Radio Beacon - carried on the Bolger brothers' boat is one of the six classes identified in last week's Marine Notice (see appendix HERE).
All were manufactured between 2005 and 2010 by Australian film GME, which has since told RTÉ News that it lately learned of problems with its radio devices via "market-place feedback".
A malfunctioning microprocessor is thought to be to blame.
RTÉ News has more on the story HERE.