Toronto Mayor Rob Ford has denied allegations that he smoked crack cocaine, his lawyer has told the Toronto Sun.
Reporters for the Toronto Star, a rival Canadian newspaper, and Gawker Media, a US media outlet, said they had seen a video that appears to show Mr Ford smoking crack.
The lawyer, Dennis Morris, told the Toronto Sun that the mayor is denying "any such allegation."
The video is allegedly being shopped around for $100,000 by people said to be involved in the drug trade. Reuters could not independently confirm the existence of the video.
Deputy Mayor Doug Holyday said he has not spoken with Ford since the allegations surfaced, but he told reporters he stands by the mayor.
"Certainly, at this point, we all know that videos can be altered and we certainly know that drug dealers can't be trusted," he said at Toronto City Hall. "So I don't know what we're dealing with here, and until we do, I don't really have much to say."
The mayor and Mr Morris did not immediately return Reuters' requests for comment.
"We're just trying to see whether or not such a video exists and whether or not any video has been doctored or altered," Mr Morris told the Toronto Sun.
Asked if Mr Ford planned legal action, Mr Morris said it is at the "bottom rung of the ladder" now.
The Toronto Star said that it stands by its reporting and that the story is just one piece of a broader investigative report about Mr Ford it has been working on for months.
"This isn't a story that we're going to report lightly," said Robyn Doolittle, one of two Toronto Star reporters who said they watched the video three times.
"This is part of an ongoing investigation that myself and a colleague, Kevin Donovan, have been working on for months," Ms Doolittle said.
She added: "The Toronto Star has a high bar that we always make sure we meet before we run something, especially when it comes to this mayor."
Mr Ford, who took office more than two years ago with a promise to "stop the gravy train" at city hall, has sparked controversy by skipping council meetings to coach high-school football and engaging in a confrontation outside his home with a reporter, among other things.
He was briefly ordered out of office in 2012 after he was found guilty of conflict of interest but won the appeal and was allowed to finish his four-year term.
Mr Ford has not been seen in public since the allegations surfaced late on Thursday.