(Reuters) -A cyber criminal has made contact with Australia's Qantas following a data breach last week that exposed personal information of six million customers, a company spokesperson told Reuters on Tuesday.

The hacker had targeted a call centre and gained access to a third-party customer service platform containing the customers' names, email addresses, phone numbers, birth dates and frequent flyer numbers.

"As this is a criminal matter, we have engaged the Australian Federal Police and won't be commenting any further on the detail of the contact," the spokesperson said, adding there was no evidence stolen data had been released but the company continued monitoring with cyber security experts.

The breach represents Australia's most high-profile cyber attack since telecommunications giant Optus and health insurer Medibank were hit in 2022, incidents that prompted mandatory cyber resilience laws.

The latest incident brings unwelcome scrutiny to the country's flag carrier as it seeks to rebuild public trust after its COVID-19 pandemic actions saw it plummet on airline and brand reputation rankings.