A video purportedly of Toronto's mayor smoking crack is causing an uproar in Canada.

The video has not been released publicly and there is no way to verify whether it is authentic. Reports by gossip website Gawker and The Toronto Star say it was taken by a man who claimed he had sold crack to Mayor Rob Ford.

Ford said Friday the allegations are "ridiculous."

The Star says two reporters watched a video that appears to show Ford, sitting in a chair, inhaling from what appears to be a glass crack pipe. The Star says it did not obtain the video or pay to watch it.

The mayor of Canada's largest city has been embroiled in constant controversies about his behavior since being elected in 2010.