Optus network failure impacted triple-0 calls in several states where patients died after 'unacceptable' lapse

Three people have died after a "technical failure" impacted hundreds of triple-0 calls on the Optus network, its CEO has revealed.

Optus CEO Stephen Rue confirmed that a technical problem resulted in the failure of triple-0 emergency calls in South Australia, the Northern Territory and Western Australia.

The calls were impacted by a network update on Thursday, the CEO said.

Two of the deaths from South Australia and one was from Western Australia.

"Our investigation is ongoing but at this stage I can confirm that approximately 600 customers were potentially impacted, of which a proportion of their calls did not go through," he said.

"During the process of conducting welfare checks, three of the 000 calls involved households where a person tragically passed away."

He confirmed the tec