The new mobile phone network 2degrees has been forced to close sections of its website due to a security breach which allowed internet users to see the contact details of other people.
The company launched its service on Tuesday.
It says the partial shutdown, which includes its online store, is the result of a bug and will only be a temporary measure.
In a statement, 2degrees says nearly 100,000 people were online on Tuesday and the privacy breach affected fewer than 100 people.
They were able to see the contact details of someone else who was on the site at the same time.