A customer is dead after their phone could not make emergency calls, putting the embattled telco industry back under the spotlight.
TPG, which also operates the Vodafone and Lebara brands in Australia, revealed a person died when their Samsung phone could not make triple-zero calls.
At the time the Sydney-based caller attempted to reach the emergency hotline through Lebara, there were no outages and the telco's network was operational.
Early investigations indicated the calls failed because the customer's ageing Samsung phone was using software incompatible with making triple-zero calls.
The error relates to a nationwide shutdown of the 3G network more than a year ago.
Some older mobile devices were configured to use the 3G network when emergency calls were placed.
"We are deeply saddened to learn of the passing of a TPG Telecom customer and extend our heartfelt condolences to their family and loved ones in this difficult time," Samsung said.
"We are continuing to work closely with our carrier partners to ensure that all devices operate reliably in every emergency situation.
"We strongly encourage customers to keep their mobile devices updated with the latest software, as this is critical to maintaining the highest standards of safety, security, and performance."
Though the death occurred on Thursday, TPG Telecom was not informed until Monday, when it received advice from NSW Ambulance.
"This is a tragic incident and our condolences and thoughts are with the individual's family and loved ones," TPG Telecom chief executive Inaki Berroeta said.
"Customer safety remains our highest priority.
"Access to emergency services is critical."
Samsung has identified 11 phones needing replacement and another 60 requiring a software update to overcome the 3G network issue.
Anyone who has not done so within five weeks of receiving notice from their telco will have their handset blocked.
The Samsung-specific issue with the Vodafone network was discovered by Telstra and Optus in late October, a year after the two telcos turned off 3G.
The federal opposition demanded the government direct all telcos to connect with more than 50,000 affected Samsung owners to ensure they update their phone or replace their device.
"I am furious on behalf of the Australian people," communications spokeswoman Melissa McIntosh said.
"The 3G shutdown happened over a year ago. So it took over a year for it to become public knowledge that these devices would not be suitable and they wouldn't be reliable."
The telecommunications industry has faced immense scrutiny following an Optus outage linked to three deaths after hundreds of triple-zero callers were unable to reach emergency services.
The latest incident and the Optus outage were part of a longstanding issue plaguing the sector, University of Adelaide telecommunications expert Mark Stewart said.
"The telcos are under a lot of pressure to move towards cheaper, more easily maintained systems," he told AAP.
"If you went wholehearted and did the best service possible for the things you're doing at the moment, then you would have to charge more than all your competitors."
He urged governments to undertake a greater overhaul of the industry to ensure telcos were caught, even for minor problems.
"The reality is, this is a socio-economic and political issue, and we need to create an environment in which the technologists are doing the right thing," Mr Stewart said.
In recent months, Optus chief executive Stephen Rue has been hauled before parliament for a six-hour grilling while the federal government has required telcos to report outages to authorities in real time.
The telecoms regulator would assess TPG's compliance with the new laws, Communications Minister Anika Wells said.
"This is a tragic situation that will be investigated," she said.
