MILWAUKEE (CBS 58) -- Milwaukee police are investigating a second instance of a possible unauthorized use of the Flock license plate tracking system, the department's chief of staff acknowledged during a Fire and Police Commission meeting.

The chief of staff said a pending investigation is underway but declined to provide further details.

The disclosure came as commissioners asked whether any findings had been made about officers using the system outside of active cases. The review follows a separate case in which former Milwaukee police officer Josue Ayala was accused of improperly using Flock to search for an ex-girlfriend.

Milwaukee police defended the technology during the Thursday, May 7 meeting. MPD Chief of Staff Heather Hough said about the trackers, "Used correctly, they are a valuable tool, and this department will not back away from that position because we really believe in it."