Nine people were arrested early Thursday morning and charged with multiple drug-related offences following an investigation conducted by the RCMP, Ontario Provincial Police, and the Toronto, Peel and York police services.

The investigation, called Project OTremens, "directly infiltrated the highest levels of traditional organized crime operating in the area," said Supt. Chris Leather of the RCMP at a Thursday news conference.

Search warrants were carried out around the GTA, in southern Ontario, and in Montreal with the help of several other municipal police forces, including Hamilton, Halton and Montreal.

In all, 75 charges were laid, including trafficking fentanyl, carfentanil, heroin, and methemphetamines. Weapons and tobacco charges were also laid, and large quantities of contraband tobacco and illegal drugs were seized.

Supt. Chris Leather of the RCMP said that the investigation's targets were 'well-known' members of crime organizations in the GTA. (Martin Trainor/CBC News)

Leather called the targets of OTremens "well-known organized crime members," noting that Canada-wide arrest warrants have been issued for three others and police are seeking a fourth arrest warrant.

The operation was conducted alongside a parallel investigation carried out by the Federal Bureau of Investigation (FBI) in New York City to infiltrate the Bonanno and Gambino crime families. Several arrests were made in New York City as well.

The investigation, said Michael McGarrity of the FBI, "unearthed and dug up the roots of a partnership extending from New York City to Buffalo and Toronto to Montreal, proving once again that Italian organized crime groups have evolved far beyond the neighbourhood cliques of days gone by."