Locations raided around the Greater Toronto Area included an apartment complex where reports have said an alleged video that appears to show Ford smoking crack cocaine was located.
Ford has said publicly that he does not use crack cocaine and the video does not exist.
Toronto Police Chief Bill Blair called the raids significant, saying they have cut off a pipeline of guns from the United States into Canada, disrupted alleged gang activity and made dozens of arrests. The investigation began with a series of violent crimes last summer, he said.
"In size there have been bigger (raids), but in importance this ranks up there with, I think, some of the most important work that we do," Blair said.
But a news conference Blair held to discuss the investigation was dominated by questions about the mayor. Blair would not say if there was any connection to Ford.
"I am not able to disclose any of the investigative methodologies that were employed in this case or to disclose any of the evidence that has (been) obtained," he said. "There is an appropriate place for that evidence to be made public and it is through a court of law."
CTV News reported that a "highly placed source" told them that on wiretaps in this investigation the alleged crack cocaine video was discussed in detail. Toronto Police were investigating the possible existence of such a video weeks before it was reported by the Toronto Star and U.S-based website Gawker, CTV reported.
The raids began Thursday shortly after 5 a.m., and involved police from multiple jurisdictions including Peel, York, Halton, Durham, the RCMP and Ontario Provincial Police as well as police in Edmonton and officers of the Canada Border Services Agency.
The investigation, known as Project Traveller, centred around the alleged activities of a gang known alternately as the Dixon City Bloods or the Dixon Goonies, Blair said.
The investigation involves such serious alleged crimes as murder, attempted murder, firearm trafficking and drug trafficking, Blair said.
Many of the alleged crimes were centred around an apartment complex on Dixon Road, the chief said.
The Toronto Star has quoted unnamed sources as saying that Ford told staff he knew where the purported video was being held — at that apartment complex.
He suggested two men in a photograph with Ford — who were both shot, one fatally, earlier this year — are somehow connected to this investigation.
"I'm aware of that picture," Blair said, when asked if police had questioned the mayor about it. "There are aspects of those individuals who form part of this investigation, but I'm unable to disclose who's been interviewed, what information has been obtained. That's part of this investigation. That information will all come out in court."
The Toronto Star reports that the same person who showed them the alleged video provided them with that picture. It shows Ford posing with one man who was fatally shot and another who was injured in that shooting.
The home of the man who survived was part of the raids, the Star reported.
But Blair would not say if the shooting is directly connected to the Project Traveller investigation.
"We know in that photograph one of those young men lost his life in a very violent incident in the city of Toronto and another one was injured and so certainly it's something that we were paying attention to and monitoring very closely," he said.
"But I'm not going to be able to discuss with you whether or not it had any relevance or connection to the investigation that we report today," he said.
Police said they would release a list of people charged Friday.
Deputy Chief Mark Saunders said 19 people were arrested in Toronto and nine in Windsor, adding that to date 43 people have been arrested in the investigation.
The gang has been "networking" with associates in Windsor, Ont., and Edmonton since 2006, Saunders said.
Police executed 39 search warrants Thursday morning in Toronto and Windsor and seized 40 firearms as well as large quantities of cocaine, heroin, hashish, marijuana, LSD, crystal meth and other narcotics, he said.
Ford said Thursday morning outside his office that he didn't know anything about the raids and had no comment on a resident's claim that an officer told her the raid was linked to the mayor.
Facing a renewed set of questions from reporters at city hall after the CTV News report broke, a clearly exasperated Ford snapped at a reporter.
"I've answered so many questions, I don't know if you guys can't get it through your thick skulls," he said. "Seriously? I've already answered all these questions. I have nothing to do with this. I congratulate the police on doing their work. That's it."
Deputy Mayor Doug Holyday said it was unlikely the police raids had anything to do with the mayor.
"The police say they were planned months ago, and it's an extensive raid, it's not just to do with that set of buildings in Etobicoke, it's throughout the GTA, involving other police forces," he said.
"Some media want to tie him to anything that goes on and that's really unfortunate."