Prime Minister Malcolm Turnbull and his most senior cabinet ministers are using a third-party messaging application to conduct confidential discussions, prompting cyber security experts to warn the innovation could actually pose a security risk.

The use of WhatsApp is not limited to senior ministers; private chat 'groups' exist for government chiefs of staff, ministerial media advisers, the frontline economic team, and a defence-focused "broadcast group" used by Defence Industry Minister Christopher Pyne to communicate with MPs and staff.

Fairfax Media has spoken with four cyber security experts who have each flagged potential security issues with the widespread use of WhatsApp by the Turnbull government – particularly at a cabinet level – in place of secure, government email servers from platforms approved by the Australian Signals Directorate (ASD), Australia's cyber intelligence agency.

Craig Searle, the founder of security consultancy firm Hivint, pointed out WhatsApp was not an approved platform on the ASD list of Evaluated Products or Certified Cloud Services, whereas Apple's iOS operating system and Blackberry's operating system were.