The hack has affected the Director-General of Premier and Cabinet Dave Stewart’s email with malicious emails circulated within the government purporting to be from Mr Stewart.
A government spokesman said police were investigating the hack, alongside the government’s chief information officer.
It comes just nine months after TAFE Queensland and the state’s Education Department were also targeted by hackers.
“Malicious emails have been received recently within the Queensland Government,” a government spokesman said.
“A police investigation led by cyber security experts is under way by Queensland Police Service, working closely with the Chief Information Officer.”
The spokesman declined to provide further details “so as not to compromise an ongoing police investigation”.
“The Queensland Government is also working with the Australian Cyber Security Centre,” he said.
“Protective measures have been further strengthened within the Queensland Government to ensure the highest security protocols exist.”
A malicious email was also circulated through Tourism and Events Queensland.