A group of Canadian journalists called on Ontario's minister of safety and correctional services Monday to order the Ontario Provincial Police to stop impersonating reporters.

It was recently revealed that an OPP constable pretended to be a journalist at a Mohawk rally held in conjunction with the aboriginal day of protest in 2007.

That tactic threatens the safety of real reporters, as well as their ability to gain access to stories and sources, the Canadian Journalists for Free Expression said in a release.

The organization also said when undercover officers pose as journalists, they undermine the public's trust in the media and infringe on the public's right to a free press.

In recent testimony at a preliminary hearing in eastern Ontario for Mohawk protester Shawn Brant, Const. Steve Martell said there are no guidelines telling officers what roles they can or cannot play while undercover.

The group asked Rick Bartolucci, the minister responsible for the OPP, to step in and direct the force to never again impersonate journalists.

"Surely, there are enough police resources and proven investigative procedures available that misrepresentation and underhanded tactics such as these do not have to be used," Arnold Amber, the organization's president, wrote in a letter to Bartolucci.