The Labour Party says the cable system connecting New Zealand with the internet has suffered a "catastrophic failure" which shows how vulnerable the country's communication infrastructure is.
Southern Cross Cable Network is the Bermuda-based company that operates the figure-eight seafloor cable link between New Zealand, Australia and the United States, via Fiji and Hawaii.
The "catastrophic" failure - because of an unauthorised and un-notified software change - happened at the Alexandria landing station in NSW on Friday morning, said Labour communications and IT spokeswoman Clare Curran.
"We understand that partial service has been restored by reinstating old circuits via New Zealand. Full restoration is still being worked on."
A spokeswoman for Southern Cross in Wellington says the incident was not as drastic as Ms Curran claimed.
“In the early hours of this morning a limited outage affecting 10 percent of our active capacity occurred during our maintenance window which is a low traffic impacting period.
"The outage occurred at one of our Sydney cable stations, Alexandria, and it lasted from 3.17am – 4.28am, Sydney Time, impacting 4 of our customers. “
But Ms Curran says the incident shows the Government's inaction and disregard for international infrastructure could have catastrophic consequences for New Zealand.
A private plan to build a $400 million 13,000km fibre cable between Auckland, Sydney and Los Angeles - dubbed Pacific Fibre - was abandoned in August due to lack of funding.