MELBOURNE, Australia — The Australian government presented its annual cybersecurity report on Tuesday, revealing that one of its national security contractors had suffered a breach in which it lost a “significant amount of data” last year.

Included in the report was a case study that said the government’s cybersecurity team discovered that an attacker had compromised the network of a “small Australian company with contracting links to national security projects,” adding that the attacker was on the network for an “extended period of time.”

Though the report outlined the breach as a case study, Dan Tehan, a minister tasked with advising the prime minister on cybersecurity, did not divulge specifics to the local news media about who was affected or what data might have been compromised. “We don’t know and we cannot confirm exactly who the actor was,” he said Tuesday on ABC Radio.

The revelation of the security contractor’s breach, and the lack of detail surrounding it, comes at a time of increased concern over the government’s ability to protect citizens’ personal information — especially when accounting for third parties that have access to sensitive data.