Two South Australian Aboriginal health services say they have had to temporarily close their clinics due to a nationwide data outage impacting some Telstra customers, which has also left three councils unable to perform critical services for almost two weeks.

Businesses using a Telstra CSX cloud service product have been without access to data and various phone, email and electronic systems since the beginning of this month.

It follows a hardware issue at one of the telco's Victorian-based data centres, which is due to close at the end of the month.

Yadu Health Aboriginal Corporation in Ceduna, on the west coast of South Australia, is one of the organisations impacted.

Its CEO, Simon Prideaux, said the corporation had been without access to patient medical records, allergy information, specialist letters or appointment bookings since June 1, prompting it to temporarily close its clinic this week.

"We've had a loss of specialists coming over with their flights, their salaries and their accommodation that we've already pre-paid.

"We've had to cancel diabetes educators because we're unable to access their bookings and phone numbers for clients, so the list is quite extensive."

The Nunyara Aboriginal Health Service in Whyalla has also had to cancel its services, including visiting specialists.

"It's very frustrating not only for the backlog of work that people are going to have to do, but for all of the patients who are really quite vulnerable, walking around not being able to access healthcare," Nunyara CEO Cindy Zbierski said.

"It's a lot safer to not provide a service and so we've been providing transport to other services and the hospital."

Ms Zbierski said although the outage happened on Saturday, May 31, the clinic's workers only found out when they turned up to work on Monday, June 3.

"At the beginning we didn't know anything, I was pushing them [Telstra] for information about what was going on.

Ms Zbierski said the service had since been able to access the list "through a third party" and had "been able to make alternative arrangements for people".

It is hoped the Nunyara clinic can reopen on Monday, June 24, while the Yadu clinic is optimistic it can open its doors next Monday, with staggered services.

"Unfortunately Telstra are very blasé at this stage, which is extremely annoying ... [because] as a health organisation we would've thought we were a priority," Mr Prideaux said.

Regional councils unable to perform critical functions

Berri Barmera Council chief executive Tim Pfeiffer said the three regional councils covering the Riverland — which also include Renmark Paringa and Loxton Waikerie — had been unable to access important data systems needed to perform critical functions for the past fortnight.

"We have certain legislative functions, we have essential services functions that we have to provide to our community," Mr Pfeiffer said.

"We have legislated time frames that we have to do these things within, which we haven't been able to meet."

Some of those essential services include property settlements, processing development applications and running local cemeteries. 

"Thankfully we've averted most of those situations with workarounds, but there have been some of those core, critical legislative functions that we haven't been able to meet."

He said the councils had moved their data from onsite servers to the cloud server to increase security.

"You never expect that this is going to happen, that as an organisation, or in this case three organisations — the three Riverland councils — that you actually lose access to your data," he said.

Mr Pfeiffer said the Riverland councils were in the process of transitioning to a different provider, and described what had occurred as a "cautionary tale".

"It has been a frustrating situation," he said.

Mr Pfeiffer said he didn't know when the system would be up and running at full capacity again, and council staff were "moving heaven and earth" to get things back online.

The Local Government Association (LGA) of South Australia said it was not aware of any additional councils being affected by the outage, which had caused an "unacceptable" level of disruption to services in the Riverland.

"It's completely unacceptable that a major network provider like Telstra can leave these councils in the dark for nearly two weeks, with little indication of when the issue will be resolved," LGA CEO Clinton Jury said in a statement.

"Riverland communities rely on their councils for core services, many of which are being impacted by these outages – it's simply not good enough and must be resolved."

Telstra 'sincerely sorry' for outage

In a statement, Telstra apologised for the outage, which it is still working to fix.

"It's been a complex issue to resolve, and our teams together with our partner have been working around the clock to bring it back online.

"In addition to recovering our cloud service platform, we've also been working with our impacted customers to find alternative solutions and resolving any remaining issues as their services recover."

In the statement, Telstra said that services for the Nunyara Aboriginal Health Service and Yadu Health Aboriginal Corporation were restored on Wednesday — but those organisations told the ABC they were still offline.

Telstra said it was also still working with the regional councils to resolve the issue.

"Renmark Paringa, Loxton Waikerie and Berrie (sic) Barmera Councils have been working with us and our partner on a transition to a Microsoft cloud platform and services are being progressively restored," the statement said.

Federal Health Minister Mark Butler said he and Indigenous Australians Minister Linda Burney heard about the Telstra outage on Friday morning.

"One of us is going to take that issue up with the Minister for Communications to see whether there is a way forward on that," he said.