(NUPGE) Correctional officers across Canada are expressing growing concern about the number of cell phones making their way through prison walls and into the hands of inmates.

The illicit presence of cell phones behind prison walls involves instances in which inmates have been caught organizing drug deals, directing criminal organizations and plotting escape.

CBC News reports that a total of 129 cell phone incidents in 57 federal prisons were recorded in Canada between 2007 and 2010, including 2 in the Atlantic region, 12 in Quebec, 22 in Ontario, 69 in the Prairies and 24 in the Pacific region.

Over the last year, three illegal cell phones have been discovered inside the walls of Manitoba prisons, says Ken Crawford, corrections staff representative for the MGEU. Contraband enters prison in various ways, including visitors.

Crawford said the problem poses an additional risk to the safety of corrections officers.

"We have no control over the discussions that are occurring between the offender and whoever they choose to talk to," he notes.

No comparable statistics are available for provincial institutions but many prison officials believe the true number of phones stashed inside correctional facilities is much higher — possibly in the thousands, CBC News reports.