Charges have been stayed for dozens of people who were arrested during Mafia raids dating back to 2014.

Crown prosecutors called for the stay of proceedings Tuesday morning.

In total, 36 people were arrested as part of Operation Clemenza between 2014 and 2016 on charges including drug trafficking, importing and producing narcotics, possession of weapons, arson and kidnapping.

It was billed by the RCMP as striking a significant blow to organized crime in the city, the largest Mafia takedown by the federal officers since the Rizzuto crime family sweep during Operation Colisee in 2006.

The 36 accused (one of whom is now deceased) will eventually see the charges against them dropped. Eleven other people will face trial as scheduled on charges related to the importation of cocaine.

Sabrina Delli Fraine told reporters that numerous factors played a part in the decision, including a recent Supreme Court ruling that set strict time limits for cases to get to trial.

But another aspect was the evidence against the accused, which in many cases consisted of intercepted Blackberry PIN to PIN messages.

Crime experts say the Crown did not want to disclose technical information about how that was done because it could compromise other investigations.

"I think that they don't want to reveal technology, but also the weakness of this technology. That's the reason why they are in a Catch 22 situation," said Daniel Renaud.

The federal prosecutor can refile charges in the cases within 12 months should the evidence warrant it.

Delli Fraine said given that police and prosecutors worked on the investigation over several years, the decision to stay the charges was made after much reflection.