Police in several Ontario communities have just conducted what may be the biggest crystal meth bust in the province's history.

'Project Newton' was an 18-month investigation that has concluded with charges against 21 people in areas including Hamilton, Halton, Niagara, Peel, Haldimand County and Sudbury.

The project was a partnership led by the Hamilton Police Service that included Halton and Niagara Regional Police Services, the RCMP and OPP.

There were some 175 officers involved in raids on 23 homes and businesses.

Drugs worth over $4 million and property such as houses and vehicles worth over $400,000 plus $140,000 in cash were seized.

Twenty-one people face more than 90 charges including; possession of anabolic steroids, cocaine, marijuana, MDMA (ecstasy) and methamphetamine (crystal meth) for the purpose of trafficking, conspiracy to traffic, possession of the proceeds of crime, production of anabolic steroids and trafficking cocaine, ketamine, methamphetamine and anabolic steroids.

A Hamilton police officer, Const. Andrew Pauls, has also been charged in the case with breach of trust, for reportedly leaking information about the investigation to a suspect.

Hamilton Police Chief Glenn De Caire said in press release, "The Hamilton Police Service remains committed to the eradication of drugs, guns and gang activity and the relentless pursuit of offenders as we work to keep our citizens safe."

The investigation is ongoing and further arrests and charges are expected.

With files from The Canadian Press.