Several emergency services departments have also launched internal investigations to determine if their data has been breached.

“The CFA is aware of claims about a potential data breach and will investigate these claims thoroughly,” a spokeswoman from the Country Fire Authority told The Age.

“We will implement any security protocols necessary to ensure the protection of personal data.”

Emergency Management Victoria has also begun looking into the claims that were first reported by News Corp.

“State and cybersecurity agency teams are currently working to investigate,” said an EMV spokeswoman.

“We take data collection and storage extremely seriously, particularly the personal information of our staff.”

A spokeswoman from the Metropolitan Fire Brigade said its data was not accessed during this breach.

“There is no information to suggest MFB has been affected at this time, and MFB has not been made aware of any breaches to any of the data we store and manage,” she said.

“MFB has safeguards in place to ensure the protection and security of any data we manage.”

Unions have also begun responding to the breach.

The Police Association secretary Wayne Gatt expressed his concerns that officers' details may have been leaked.

“This situation is deeply worrying. The Police Association has not been advised of this breach or how many of its members’ personal information has been compromised. We are currently trying to ascertain those details," he said.

Peter Marshall, the Victorian branch manager for the United Firefighters Union of Australia, said the union was not aware of the breach but would begin speaking with people on Monday.

Victoria Police have been contacted for comment.