In short:

TPG Telecom has confirmed a customer in Sydney died last week after a mobile phone could not make Triple Zero calls.

The telco says early investigations indicated the failed calls were due to a Samsung device operating on software that was not compatible with making Triple Zero calls on the network.

Samsung said on its website it had identified older mobile devices that do not "correctly connect to an alternative mobile network to make Triple Zero calls when the user's primary network is not available".

The company lists on its website dozens of devices that need to be updated or replaced to ensure users can make Triple Zero calls.