The Internal Revenue Service (IRS) has owned at least one Stingray, according to documents recently obtained by the Guardian through a Freedom of Information Act (FOIA) request.

Invoices show the agency made purchases in 2009 and 2012 from Harris Corporation, the company company that makes surveillance equipment.

While the mostly redacted 2009 IRS/Harris Corp. invoice doesn't yield many details, the 2012 invoice reports shows the agency spent $65,652 on upgrading a Stingray II to the more powerful HailStorm as well as $6,000 on training from Harris Corporation.

A former IRS deputy commissioner for services and enforcement told the Guardian it is unclear how the equipment was used but noted that the agency does participate in joint initiatives with other agencies, such as the Federal Bureau of Investigation (FBI), to shutdown money laundering operations. Those efforts might require the use of the surveillance technology.