A security breach which affected the ACT government's email gateway system has suspected links to China.
The system, Barracuda, was compromised last month but the territory government says, at this stage, there is no "definitive evidence" that information has been removed.
Barracuda Networks, in a statement, said the breach was committed by an "aggressive and highly skilled actor" which had suspected links to China.
Special Minister of State Chris Steel issued an update on the ACT government's situation on Thursday, saying all the government's ICT systems were running normally and could be used with confidence.
He said the vulnerability had been eliminated and the "rebuilt system" showed no ongoing signs of any vulnerabilities but it was believed a breach has occurred.
"We believe a breach has occurred and the forensic investigation of our system is ongoing," Mr Steel said.
"At this stage we have no definitive evidence that any information has been removed."
The ACT government has not been contacted by anyone claiming to be responsible.
The issue with the Barracuda system was notified to system users on May 24, prompting the ACT Cyber Security Centre, which was established last year, to investigate, the government said.
Mr Steel said last week that information provided to the ACT government in digital forms - which then send a copy of the form back to the person who submitted it in an email - was the type of data most likely to be affected.
The government has ramped up its monitoring and cyber security processes in the wake of the incident.
"We are running increased monitoring and cyber security processes as well as continuing to investigate any systems that interact with the Barracuda gateway to determine any potential harm," Mr Steel said.
"We are working closely with the Australian Cyber Security Centre and our Chief Information Officer network to complete these assessments as soon as possible."
There is currently no requirement for any action by the community, the government has said.
