TORONTO, Cananda – Toronto’s embattled mayor has told ex-media mogul Conrad Black he’s willing to submit to a urine test to prove he has no drugs or alcohol in his system.

Rob Ford’s comments have aired in a promotional clip for an interview with Black that was recorded last week and will air on Vision TV on Monday night.

Ford has been under scrutiny since May, when two media outlets reported the existence of an alleged video which showed the mayor smoking what appeared to be crack cocaine.

After a string of denials, Ford stunned observers last month by admitting he had smoked crack in one of his “drunken stupors.”

The mayor is also facing allegations he offered purported gang members money and a car in exchange for a video — unproven claims contained in police documents that are part of a guns and gangs investigation.

Meanwhile Black — who served 37 months in a Florida prison after being convicted in the U.S. for fraud and obstruction of justice — says Ford should be accorded a full presumption of innocence unless he is justly convicted and “beyond that his accusers should put up or shut up.”

Black has argued repeatedly that the U.S. case against him was the result of an unfair prosecution.