Three London homes were raided early Tuesday morning as part of an RCMP investigation into an illegal gambling operation.
Provincial police executed warrants at homes on McCracken Court, Gatenby Street and Locust Crescent.
Raids were also conducted across southwestern Ontario, with arrests made in Toronto, York Region, Barrie and London.
The raids are connected to a bust at a Super Bowl party held at a banquet hall in the Greater Toronto Area where six people were arrested, and $2.5 million in cash and computers were seized.
The February bust followed a two-year investigation into an offshore sports-betting company known as Platinum Sports Book, which is believed to have ties to organized crime.
OPP Deputy Commissioner Scott Todd says "As it went along the investigation uncovered disturbing threats and acts of violence including extortion and intimidation."
That same day homes and businesses in the GTA were searched and the Platinum SB website was shut down. Six people believed to be at the head of or key members in the organization, including a London man, were arrested.
According to RCMP Superintendent Keith Finn Tuesday’s arrests “Have rolled up, shall we say, the rest of the management team
While police faced criticism when some of those arrested on Super Bowl Sunday were quickly released and the website quickly re-established, they now say it was part of the strategy.
"When individuals were, in fact, shall we say scrambling to re-establish the web site and the criminal enterprise. The fact is that those individuals at large provided us with key evidence," Finn says.
Local police forces, the OPP and RCMP were all involved in the raids and say the 18 locations targeted yielded significant evidence.
York Regional Police Deputy Chief Bruce Hedridge says "Approximately $1.6 million cash, two hand guns, a taser, numerous computers, cell phones, betting lists, ledgers, bank statements, drafts and documents relating to criminal organizations were seized."
Names of the 18 arrested and four people still being sought are expected to be released on Wednesday. Charges all relate to bookmaking and participating in an organized criminal activity.