Delay in Telstra alerting communications minister to outage revealed

Anika Wells says welfare checks related to Triple Zero calls are "ongoing". (ABC News: Joel Wilson)

Telstra officials notified the office of Communications Minister Anika Wells about a widespread mobile and data outage hours after initial problems were detected.

The network crash has sparked a political stoush over a senior Liberal test-calling Triple Zero, as well as unfounded suggestions of foreign interference.

Telstra says the issue is resolved and that services will be restored in the coming hours as police continue to conduct welfare checks on Triple Zero callers.

Telstra informed the office of Communications Minister Anika Wells about a widespread mobile outage potentially impacting millions of Australians about two and a half hours after first detecting an issue.

State and territory police have been conducting welfare checks on dozens of individuals who had calls to Triple Zero (000) drop out during the network crash on Wednesday, which also stalled regional train services and affected payment processing for businesses.

A senior Liberal has also denied breaking the law by test-calling the emergency number to ascertain if there were connection issues, a move criticised by Labor as "outrageous".

Telstra reported that as of 4pm the problem had been resolved and remaining affected services would be restored within hours.

Telstra says its services have been mostly restored after a nationwide outage that impacted potentially millions of Australians.

The telco first identified a problem impacting "some" mobile phone calls and data services at about 4.30am on Wednesday, with Telstra advising Ms Wells's staff about the network crash at about 7am.

The information was immediately passed on to the minister, who returned from leave to respond to the situation and declared it was on Telstra to explain to Australians how and why it had happened.

Telstra has defended its communication process, insisting the government and other stakeholders were informed "very, very early" in the morning.

Ms Wells said a "detailed" timeline of the incident was being collated by Australia's Triple Zero custodian, noting this was one of the lessons from last year's Optus outage.

Ms Wells said telcos were already the least-trusted industry in the country and that it would be up to Telstra to "make things right".

She also confirmed the government had been advised that some callers had been unable to connect to Triple Zero and as at 10.25am about "three dozen" welfare checks were ongoing.

"The Triple Zero custodian is in regular communication with Telstra to receive up