Toronto police say dozens of gang members and a Hamilton police officer were arrested after officers dismantled a mid-level street gang.

A joint task force executed 50 search warrants in an area spanning from Barrie to Hamilton early Thursday morning as part of a months-long investigation into a Toronto-based gang.

"The investigation was launched based on credible evidence indicating that the 'Monstarz' street gang was engaged in extensive criminal activity that posed a direct and very real threat to community safety," Acting Toronto Police Chief Jim Ramer said Friday.

The gang operates in the northwest quadrant of Toronto, but has ties in the Peel, Halton, Bradford, Durham, York, Niagara and St. Catharines areas.

Members of the gang had been involved in 44 recorded incidents of violence in and around the Rexdale area since May 2011, Ramer said at a news conference.

The incidents included robberies, shootings and homicides, with direct links to trafficking of illicit drugs and firearms, Ramer said.

Over the last nine months, investigators have worked with other local police forces as well as the Ontario Provincial and Royal Canadian Mountain Police to dismantle the gang and its affiliates, Ramer said.

The investigation led to the execution of 50 search warrants conducted simultaneously in an area spanning from Barrie to Hamilton on Thursday morning. Police said that a large quantity of drugs, guns and cash were seized in the raids. Officers said 45 people were arrested on Thursday morning, and 27 had been arrested at earlier dates.

"These arrests have removed many violent and armed criminal gang members from our communities," Ramer said.

Among those arrested was a Hamilton police officer, he said. Officer Craig Ruthowsky, 41, was charged with breach of trust, conspiracy to commit and indictable offence, participating in activities of a criminal organization and commission of an indictable offence for a criminal organization.

The 17-year veteran of the Hamilton Police Service has been suspended with pay since June 2012, and Hamilton police are working with Toronto officers as they investigate his alleged involvement in the Monstarz gang.

Arrests made in 2014 Etobicoke shooting

Police said the Monstarz gang was behind several violent incidents across the city. One of the incidents was a shooting that occurred at an apartment complex on Mount Olive Drive, in the area of Kipling and Finch Avenues on May 30, 2014. Three people were injured in the shooting, and one of the victims was taken to Etobicoke General Hospital.

Police said the suspects followed the victim to the hospital and opened fire in the area, injuring another person. The hospital was locked down for a period of time following the shooting.

"These events were determined to be directly linked to a gang feud involving the Monstarz street gang," Ramer said.