Two Toronto police officers and three corrections officers are among 20 people charged in a large-scale marijuana drug trafficking operation in the Greater Toronto Area.

Toronto Police Chief Bill Blair said officers made the arrests after executing 63 search warrants throughout the region early Thursday morning.

Blair said evidence from earlier marijuana grow-op busts in York region allegedly linked the Toronto officers to a larger criminal network.

"The primary purpose (of the organization) was the production and distribution of marijuana, the distribution of other drugs and the laundering of the proceeds of their criminal enterprise," Blair said at a press conference late Thursday afternoon.

The chief said officers conducted months of surveillance during an "exhaustive and lengthy investigation."

The majority of the alleged criminal activity occurred in York.

Thursday's pre-dawn raids, which were carried out at homes and businesses, netted 17 pounds of marijuana and $60,000 in cash, said Supt. Jim Ramer.

Ecstasy and steroids were also allegedly being distributed. Ramer said officers seized a large amount of drug-making equipment.

Police aren't yet releasing the value of the drugs and the total figure of the drug operation.

The two officers charged have been identified as Const. Kevin Bourne, a nine-year veteran, and Const. Patrick Lee, an eight-year veteran. They have both been suspended with pay.

The officers face numerous charges, including production of a controlled substance, trafficking a controlled substance, obstruction of justice and breach of trust.

Blair said this is the first time his officers have been linked to a grow-op.

Seventeen other adults, including three corrections officers, and one youth, have been charged in the investigation. They are scheduled to appear in a Newmarket court on Friday.

The jail guards were employed at the Toronto West Detention Centre in Rexdale, and the investigation probed whether drugs were making their way to inmates, CTV News has learned.

Police expect to release more details and the names of the other accused on Friday.

With a report from CTV Toronto's Tom Hayes