Singapore Telecommunications said on Monday it was assessing the potential costs of the massive cybersecurity breach at its Optus arm, Australia’s second-largest telco, 12 days ago.

In its second comment on the breach of private data from 10 million accounts, Singtel sought to clarify reports it could face a huge compensation bill.

It said it has not received any legal notice of a class action lawsuit but has engaged lawyers to advise it.

Any class action will be vigorously defended, if commenced, Singtel said in a statement.

Singtel is continuing to evaluate the potential #financial implications arising from this matter and any material development will be disclosed to the market on a timely basis, the company said.

At least two major law firms, Slater & Gordon and Maurice Blackburn, have said they are investigating a possible class action against Optus to claim compensation for people affected by the breach.