The number of drugs, weapons, booze and other banned items seized in Canadian prisons increased more than 20 per cent over the last two years, as the Correctional Service of Canada seeks sweeping new powers to further crack down on contraband.

But some prisoner advocates say the proposed changes — to allow more intrusive and frequent searches and restrictions on visitors — could hamper rehabilitation and ultimately compromise public safety.

Data obtained by CBC News under Access to Information shows CSC seized 8,980 unauthorized and contraband items behind bars in 2013-2014, up from 7,458 items two years earlier, an increase of 20 per cent. The number of seizure incidents dropped by about 11 per cent, to 6,200 in 2013-14 from 6,871 in 2011-12.

The list of contraband seized includes marijuana, hash and drug paraphernalia and hard drugs such as crack cocaine, crystal meth, LSD and ecstasy. Dangerous weapons were also seized, including explosives and incendiary devices, hacksaws, rope and thousands of weapons hand-made by prisoners. And 108 televisions were intercepted last year alone.

Other unauthorized or contraband items seized in federal penitentiaries:

Alcohol: Distilled and brewed alcohol, material for making alcohol, store-bought booze.

Tobacco: Cigarettes, cigars, loose tobacco.

Communications devices: Cellphones, cameras, cables, computer components, SIM cards and storage devices.

Other: Government property, pornography, tattoo guns and paraphernalia, money, security keys and a grappling hook.

The items were seized from inmates, the public and corrections staff.

CSC spokesman Jonathan Schofield said the spike is due to enhanced security measures brought in to stem the flow of drugs and other contraband into institutions, including increased searches, random urine tests, and tools such as metal detectors, X-rays, drug-detecting ion scanners and dogs. Enhanced perimeter security measures such as towers and watch points have also prevented more drugs from being thrown over fences and walls.

"Considerable resources are focused on these approaches because addressing substance abuse problems is an important factor for ensuring successful reintegration into the community," Schofield said.

But CSC wants to take further steps to clamp down on drugs and other contraband. A public consultation process is now under way on a series of regulatory changes and is expected to finalize proposals this fall.

Concern over effect on prison visits

Advocates worry the changes could deter prison visitors, who they say are integral to prisoners making a smooth transition back into the community after their release.

Catherine Latimer, executive director of the John Howard Society of Canada, said many family members and volunteers who are important to the successful reintegration of prisoners are already discouraged from visiting because of the onerous drug screening procedures already in place. She said a greater emphasis on treating addictions and harm reduction would be more effective than more intrusive screening measures and restricted visits.

"Studies show that those who have maintained family contact while incarcerated are less likely to re-offend. Involvement with volunteers, such as teachers and community visitors, can also make a big difference to correctional success," she said. "Maintaining contact with support networks outside of prisons is very important to successful rehabilitation and reintegration."

Howard Sapers, the Correctional Investigator of Canada, said family visits are important and they are not the primary source of contraband making its way inside.

"There's no evidence to show that this spike is because people are smuggling things in through an infant's diaper. In fact, just the opposite," he told host Evan Solomon during an appearance on CBC News Network's Power & Politics.

"You're less likely to find something coming in through a legitimate visit than you are from other sources — other people coming in to the prison, sometimes even trusted people .... staff. So focusing just on visitors is out of balance with where the problem is."

Jason Tamming, spokesman for Public Safety Minister Steven Blaney, said the government is committed to cracking down on drugs with random drug tests, detector dog training and mandatory prison sentences for selling drugs in prisons.

"While it sounds like it should be common sense that there are no illegal drugs behind bars, it sadly is not. There are nearly 1,500 drug seizures in prison each year," he said in a statement to Power & Politics.

"The NDP want to have a needle exchange for prisoners. Rather than supporting the habit of using illegal drugs, our government is focused on keeping drugs off our streets and out of our prisons."

Tamming said the government has also introduced the Drug-Free Prisons Act, which will give explicit authority to the Parole Board of Canada to cancel parole after a positive drug test, reinforce the board's ability to apply conditions to ensure parolees are not using drugs outside prison and enshrine the definition of a positive drug test in law, so there is no confusion on the part of bureaucrats.