Politician again disputes claims of a video showing him smoking crack cocaine despite reports from Toronto Star and Gawker

Embattled Toronto mayor Rob Ford has denied that a video of him smoking crack cocaine exists, and blasted media chasing the story as "a bunch of maggots".

In comments unlikely to improve Ford's rocky relationship with the city's press, the mayor suggested that good journalists were "few and far between" during a weekly radio show he hosts with his brother, Doug Ford, a city council member.

It came just days after the mayor was forced to again deny allegations that he uses crack cocaine. At a press conference on Friday, which broke days of silence over the issue, Ford described the claim as nonsense. "I do not use crack cocaine, nor am I an addict of crack cocaine," he said.

But he refused to answer questions from journalists, and his denial fell short of outright denial that he had ever used drugs in the past.

During Sunday's broadcast, Ford again declined to confront allegations over any history of drug use but did address a question from a listener over a clip purportedly showing him smoking crack.

"Number one: there's no video, so that's all I can say. You can't comment on something that doesn't exist," he said.

The alleged crack-smoking video has not been released publicly but reports on gossip website Gawker and in the Toronto Star claimed it was taken by men who said they sold drugs to Ford.

Journalists at the two organisations have written lengthy descriptions of a video they say they have watched, and Gawker even launched a campaign to raise $200,000 to buy the video and publish it.

As of Monday morning, the online appeal had raised $184,875. But even if the total is reached, plans to purchase the video could fall apart due to the unreliability of the sellers, Gawkers has cautioned.

"The last time we established contact with the people who are in possession of the video was this past Sunday, and we have not been able to reach them since," posted Gawker editor on Thursday, adding that the website's confidence in getting the deal done had "diminished".

Reporters from the Star who have seen the video have said that it appeared to show Ford sitting in a chair, inhaling from what seemed to be a glass crack pipe. The Star also reported that in the video Ford allegedly made a homophobic slur and made a racist remark about high school football students he coached.

Ford has been embroiled in almost weekly controversies about his behaviour since he was elected in 2010. The Toronto Star reported earlier this year that he was asked to leave a gala fundraiser for wounded Canadian soldiers because he appeared to be intoxicated.

During his campaign for mayor, Ford vehemently denied a 1999 arrest for marijuana possession in Florida; he later acknowledged it was true, after confronted with evidence. He pleaded guilty to driving under the influence and failing to give a breath sample to police.

Yet the crack allegations have no doubt been the biggest scandal to hit Ford, creating headlines around the world and becoming the subject of endless jokes on late-night comedy shows. Last week, the executive committee of Toronto city council – which acts as sort of cabinet to the mayor – released a letter asking Ford to address the allegations "openly and transparently". That came a day after Canadian media reported that Ford's chief of staff, Mark Towhey, had been fired after telling the mayor to go to rehab.

But despite calls for him to step down amid the allegations, Ford has indicated that he intends to ride out the scandal and seek re-election next year.

"I'll be the first putting my name on that ballot," he said.

Meanwhile, brother Doug Ford used Sunday's broadcast to address separate claims that he sold marijuana for several years in his youth.

"I was not a dealer of hashish in the 1980s," he told listeners.