This admission was made in a joint statement with UniSuper chief executive Peter Chun on Wednesday. Google Cloud was responsible for the misconfiguration.

But the statement is hidden in a list of FAQs and cannot be linked to directly.

The problems with UniSuper members accessing their accounts has been going on since last week.

"This should not have happened. Google Cloud has identified the events that led to this disruption and taken measures to ensure this does not happen again.

"UniSuper had duplication in two geographies as a protection against outages and loss. However, when the deletion of UniSuper’s Private Cloud subscription occurred, it caused deletion across both of these geographies.

"Restoring UniSuper’s Private Cloud instance has called for an incredible amount of focus, effort, and partnership between our teams to enable an extensive recovery of all the core systems.

"The dedication and collaboration between UniSuper and Google Cloud has led to an extensive recovery of our Private Cloud which includes hundreds of virtual machines, databases and applications.

"UniSuper had backups in place with an additional service provider. These backups have minimised data loss, and significantly improved the ability of UniSuper and Google Cloud to complete the restoration."

In a second FAQ, dated 9 May, UniSuper said: "Members can now log in to their accounts, view their balance and see the up-to-date investment performance for their accounts.

"Please note, that account balances shown may not reflect transactions which have not yet been processed due to the outage. We are working to get these updated as quickly as possible.

"Transactions will not be possible through the online platform at this time. We are working to progressively restore all functionality as quickly as possible and will keep members updated."