The discovery of a listening device in a smoke detector at the Saskatoon Correctional Centre is raising questions for the provincial government.

Jail officials admitted that the device was installed around April 1 in a smoke detector in the remand unit staff lounge. But acting director Jock McDowell at the Saskatoon Correctional Centre said it was there for testing and never used to record conversations.

"No other prototype intercom devices were installed anywhere else in the correctional centre, nor did the system have any storing or recording capacity," he wrote in a letter to union staff at the jail.

"No personal information was collected, stored, transmitted, or in any way accessed."

Who ordered what, and when?

Greg Fleet, with the John Howard Society, a prisoner advocacy group, said the possible use of hidden microphones in various parts of the jail is concerning.

Not everyone in jail has been convicted of a crime. Almost half the people at the Saskatoon jail are there awaiting trial and have not been convicted of anything.

"Inmates have very little privacy as it is," he said. "We know that their telephone conversations are being recorded and monitored. This could be another level. Where does the monitoring stop," he said in an interview.

Fleet said he also wonders who authorized the use of the device and on what legal authority.

A Corrections official told CBC on Monday that the use of the device came from two violent incidents at two different jails. An inmate was murdered at the Saskatoon jail and another committed suicide at the Prince Albert jail.

It's not known whether the listening devices are currently in use in any jails.