TORONTO (REUTERS) - Toronto Mayor Rob Ford, under pressure to respond to allegations he was filmed using drugs, said on Friday that he does not smoke crack cocaine and could not comment on a video he had not seen or does not exist.

"There has been a serious accusation from the Toronto Star that I use crack cocaine. I do not use crack cocaine, nor am I an addict of crack cocaine," he told a news conference.

The Toronto Star and Internet gossip blog Gawker reported last week they had separately seen a cellphone video that allegedly shows Mr Ford smoking a substance from a crack pipe while in the company of people involved in the drug trade.

"As for a video, I cannot comment on a video that I have never seen or does not exist," said Mr Ford, who did not take questions from reporters.

His comments mark his first direct response to the allegations since the Star and Gawker stories were published last Thursday.

Shortly afterward, he called the reports"ridiculous," but did not give a full statement or denial.

Since the allegations surfaced, he has been hounded by news media at every turn, while several city councillors and allies have encouraged him to confront the issue directly.

The Toronto Sun, a right-leaning newspaper generally considered to be Ford-friendly, published an editorial on Thursday demanding the mayor either strongly deny the allegations or step down from office to seek medical help.

Earlier on Friday, six members of the mayor's executive committee, including Deputy Mayor Doug Holyday, published an open letter to the mayor urging him to confront the allegations.

Mr Ford told reporters he had remained quiet on the advice of his solicitor.

The video, which Reuters cannot independently verify, is allegedly being shopped around by people involved in the drug trade. Gawker launched a "Crackstarter" campaign to raise US$200,000 (S$253,124) to buy it and publish it online.

The controversy, meanwhile, has made headlines across Canada and around the world, and drawn ridicule from late-night TV humorists Jimmy Kimmel and John Stewart.

On Wednesday, Mr Ford lost his much-loved job as a volunteer high school football coach, and on Thursday he fired his chief of staff.

This is not the first controversy for Ford, who has drawn criticism for skipping city council meetings to coach football and engaging in a confrontation outside his home with a reporter.

He was briefly ordered out of office in 2012 after being found guilty of a conflict of interest, but won an appeal and was allowed to finish his four-year term.