A South Australian senator is standing by allegations a person died because of Wednesday’s Telstra outage, despite police denying any knowledge and a spray from the state’s police minister.

Senator Kerrynne Liddle said her office had been told South Australian resident had died after being unable to contact triple zero.

She posted on Facebook of the “tragic death” on Wednesday.

“The death of an elderly South Australian represents a devastating failure for their family. Our thoughts are with them,” Liddle, a Liberal senator, wrote.

“No Australian should ever be unable to contact triple zero when their life depends on it.”

Her claims came as Telstra users faced a second day of outages, with another bug preventing triple zero calls from connecting as welfare checks continued.

But SA Police said they were unaware of any fatalities due to issues with triple zero. SA Police Minister Michael Brown said it was “downright dangerous” for Liddle to publicly share “speculative information”.

“Parliamentarians have a special obligation. We have an obligation to do things honestly and do things fairly,” he told InDaily.

“When we get information, we should take the steps to actually check that information is correct before we put it out in the public arena.

Brown said Liddle was yet to provide further information to police.

“As I understand it today, they are seeking to contact her again and get information from her, and I would call on her to reveal the information that she has,” Brown said.

“She doesn’t need to do so publicly, but she at least needs to help police understand what’s going on and get to the bottom of the situation.”

Later on Thursday, Liddle posted again to Facebook, standing by her claims.

“On Wednesday, my office received a report that an elderly South Australian had died during the Telstra network outage that morning,” she wrote.

“After contact from Telstra, media and relevant authorities, my office advised the family to reach out to SA Police directly. The grieving family did that today.”

She said she was “disappointed” that Brown had fronted the media to question her integrity.

“Amid much public interest I prioritised the privacy of the family during this time. I stand with them,” she wrote.

The outage halted regional trains across Victoria, causing chaos. Photo: AAP

Second glitch hits Telstra

The communications regulator has opened an investigation into the widespread Telstra disruption that hit transport, businesses, emergency services and healthcare.

While the issue was largely resolved by mid-morning on Wednesday, a separate “secondary issue” prevented some users from making triple zero calls.

Telstra advised customers to immediately retry emergency calls if they did not go through, with 639 welfare checks conducted to date.

On Thursday, chief financial officer Michael Ackland again fronted media, describing the back-to-back technical mishaps as “an unfortunate incident” that was unacceptable to customers.

“While we addressed the original issue, that subsequent issue remained ongoing and needed to be addressed in a different way,” he said.

“Mobile networks are complex, and we will continue to work through further changes to ensure we have the most robust solution but customers can feel confident in calling triple zero.”

The company said overnight work had reduced the separate triple zero error by about 90 per cent as engineers continued to eliminate the bug.

Telstra said the volume of welfare checks was higher than expected.

Ackland said the company had completed 639 welfare checks since Wednesday morning. Of those, 402 cases required followed-up voice calls, with 170 calls passed to police.

Seven callers advised they needed assistance, Ackland said.

“Any one missed call is unacceptable,” he said.

Ackland referred questions about the possible fatality in South Australia to police.

Telecommunications Industry Ombudsman Cynthia Gebert said there were still gaps in the emergency communications system that needed to be plugged immediately.

“It’s fair to say the Telstra outage yesterday shines a further light on the whole triple zero ecosystem to work much more effectively for end users than it did,” she told ABC News on Thursday.

Elsewhere, transport operators continue to deal with the fallout from outage.

All regional V/Line train services across Victoria were suspended as signalling systems were tested following the outage.

“Trains will gradually return from midday Thursday,” the operator posted to social media. “Delays and cancellations may continue across the day as we work to recover the full timetable.”

It thanked passengers for their “patience and understanding during this challenging time”.

Transport for NSW said regional TrainLink services were also resuming. Intercity train services had also begun again on the Southern Highlands and Hunter lines.

The outage began about 4.30am on Wednesday after a software issue affected nodes responsible for keeping time across Telstra’s mobile network.

The disruption left customers unable to make some calls or access mobile data, while EFTPOS terminals and business services were also affected.

Experts say Wednesday’s outage exposed just how reliant critical infrastructure is on a handful of telecommunications providers.

It is the third major national outage in less than a year for the $56 billion giant, which powers about 25 million Australian mobile services.

-with AAP