The Australian Federal Police has been caught out using civilians in undercover operations without proper authorisation.
The Commonwealth Ombudsman, in a report tabled in parliament on Monday, found at least a dozen instances in 2015.
Most were disclosed by the AFP themselves, but some were uncovered during inspections by the Ombudsman.
In one case, a civilian "engaged in activities" relevant to a covert operation without the AFP knowing nor being listed as a participant.
Even after the AFP found out, the person continued to participate without proper protections.
In another instance, a civilian was directed by a police officer to engage in activities related to a controlled operation before it had even been authorised.
If someone isn't listed as a participant and is not acting in accordance with instructions of a law enforcement officer, their actions could be deemed illegal.
"When agencies involve civilians in a controlled operation, we are of the view that it is important for that agency to take appropriate measures to provide protection for the civilian so that they are not unfairly subject to criminal and civil liability, and keep records to demonstrate this," the report said.
The Ombudsman has recommended the AFP provide more targeted training to relevant staff, to which they have agreed.
It noted that given the AFP self-disclosed most of the issues it had no concerns about transparency and accountability.
"However, given the high level of risk associated with these instances of non-compliance, we will continue to monitor these issues closely."