The confirmation follows the announcement by a 2GB Radio Sydney announcer on 10 March 2011 that he was in possession of the USB stick, which was claimed to contain Defence classified information.
In a statement, Defence said it collected the USB stick on the same day, and assessed whether it did contain classified information. "Initial analysis indicates that the device does contain Defence information, none of which is highly classified and some which is unclassified and available over the internet," the statement reads.
Defence did not comment on whether the data contained on the stick was encrypted or able to be copied.
According to Defence, the memory stick's owner had been identified as a former Defence member and current contractor.