Ontario Provincial Police have charged 23 people after an eight-month investigation into the trafficking of illegal firearms and drugs by an organized crime group in the Greater Toronto and Golden Horseshoe areas.

The accused are believed to have manufactured and distributed "untraceable" firearms by using unregulated parts, according to the OPP, which did not disclose where exactly the weapons were allegedly made.

Police said they seized 14 handguns, six long guns including a machine gun and assault rifle, silencers, grenades, a stun gun and body armour.

They said officers also seized 1.2 kilograms of cocaine, 30 grams of crystal meth, 13 grams of heroin, 66 fentanyl tablets and $85,000 in cash.

OPP Deputy Commissioner Rick Barnum said the investigation, dubbed Project Renner and conducted by the OPP-led provincial weapons enforcement unit, is significant because trafficking in illegal firearms threatens public safety in Ontario.

"We've taken a bunch of guns out of circulation, which could have been used for further crimes to maim and to kill people," Barnum said at a news conference in Vaughan on Tuesday. "Because of this work, our communities are safer today."

Police said the guns have been seen on Toronto streets as early as 2016.

The 23 accused face a total of 156 charges. Two of the accused, considered to be group leaders, are believed to have manufactured and trafficked more than 120 handguns.

Officers also seized four vehicles and a residential property.

Police said they seized 1.2 kilograms of cocaine, 30 grams of meth, 13 grams of heroin, 66 fentanyl tablets and $85,000 in cash as part of the investigation. (Ontario Provincial Police)

At the news conference, Barnum told reporters that the investigation was complex, time-consuming and took months of police work.

"The people charged and the weapons that we have seized are all linked to the typical facets and activities that are synonymous with organized crime, gun violence, affiliation to known criminal groups, street gangs, human trafficking, drug manufacturing and distribution," he said.

'Tools of the trade'

"The photos of the evidence alone accurately depict the tools of the trade used by these criminals."

OPP said the investigation began in April 2018 as a probe by the OPP's organized crime enforcement bureau into an organized crime group that had allegedly been producing restricted and untraceable firearms using unregulated parts. The OPP-led provincial weapons enforcement unit is part of the bureau.

According to the OPP, the group manufactured illegal guns to be distributed to "multiple criminal cells" in Ontario.

Ontario Provincial Police created this collage of photos that depict the 14 handguns, six long guns, 1.2 kilograms of cocaine and other drugs seized in an investigation with other police forces. (Ontario Provincial Police/Twitter)

More than 400 police officers from several police forces executed 39 raids late last week across the GTA, Barnum added.

Several police forces took part in the investigation, including the Durham, Peel, Halton, Hamilton and Niagara regional police. Other police forces, namely the Toronto, Barrie and London police, as well as the RCMP, helped to carry out search warrants and make arrests.

The people charged are expected to appear in court in the near future, the OPP said. The accused are from Toronto, Mississauga, Brampton, Milton, Hamilton, Rockwood and Smithville, Ont.

Charges include:

Conspiracy to commit an indictable offence.

Participation in a criminal organization.

Trafficking in firearms, weapon, device or ammunition.

Possession of loaded prohibited or restricted firearm.

Possession of firearm knowing the serial number has been tampered with.

Possession of a schedule 1 substance for the purpose of trafficking.

Police said they don't believe the organized crime group has a name.