Starting Wednesday, Qantas has been sending emails to around 5.7 million affected customers, outlining exactly what details were exposed due to a breach of their call centre system.

However, some customers have today received a second email from the airline, informing them more data had been stolen than first thought.

A spokesperson from Qantas revealed to 9news.com.au that, for most customers, the ongoing investigation uncovered that their phone numbers had also been accessed, in addition to the information they were alerted about earlier that week.

The precise number of people who received this follow-up email remains uncertain, but Qantas earlier disclosed that approximately 900,000 individuals and businesses had their phone numbers stolen in the breach.

“We are writing to provide you with an update following our previous email about the cyber incident on Monday, 30 June 2025,” the emails seen by 9news.com.au read.

“Our ongoing investigation has identified that your phone number details were accessed in addition to the data types we previously advised.

“We recommend you remain vigilant for any unexpected contact by phone, in addition to the email and text message precautions we outlined in our previous communication.”

However, it has stressed no login details, credit card numbers, payment details or passport numbers have been compromised.