Witnesses claim Ford became "enraged" with Bieber during a night of drug-fuelled partying, after the pop star made a joke about crack cocaine.
On Thursday, the Toronto Star reported that Ford and Bieber encountered each other at Toronto's Muzik nightclub on 15 March. The embattled mayor was about to shake the singer's hand when Bieber quipped, "Did you bring any crack to smoke?" Infuriated by the joke, Ford allegedly had to be escorted back to his booth by security.
Witnesses claim they saw the mayor drinking to excess until 5am. In a separate incident, on 5 April, he was reportedly seen snorting lines of cocaine. "My wife and children hate me. I am in over my head," Ford is alleged to have said.
Ironically, Ford championed Bieber when the Baby singer's behaviour was criticised earlier this year. "He's a young guy," Ford said in a January radio interview. "Think back to when you were 19 … At 19 years old, I wish I was [as] successful as he was."
Ford announced on Wednesday night that he is "stepping away" from his official duties, and – for the time being – from the mayoral election campaign, to seek treatment for substance abuse.
"I have a problem with alcohol, and the choices I have made while under the influence," he said in a statement. "I know that I need professional help and I am now 100% committed to getting myself right."
Ford's lawyer told the Associated Press that Ford is to undergo a 30-day rehab course.
guardian.co.uk © Guardian News and Media Limited 2010