A woman uses her mobile phone as she walks past in front of an Optus shop in Sydney, Australia, February 8, 2018.
Optus Chief Executive Kelly Bayer Rosmarin said there was lot of "misinformation out there".
Rosmarin said Optus had briefed authorities after the government's initial review of the incident.
Stolen data posted in an online forum has been deleted and hackers have apologised to Optus, the reports said.
Australia's Council Of Financial Regulators, which includes the central bank, on Tuesday said its members have been working together in response to the cyber attack.