11/01/2013 07:35 EDT | Updated 01/23/2014 06:58 EST

Rob Ford's friend Alexander Lisi due in court today

Rob Ford's friend and occasional driver Alexander Lisi will appear in a Toronto courtroom today to face an extortion charge,one day after police confirmed they have a tape that apparently shows the Toronto mayor smoking crack cocaine.

Details of police surveillance were released Thursday, and show a flurry of phone calls and meetings between Ford and Lisi in the days after the crack video story first broke in mid-May. The documents were filed by police in their efforts to obtain a search warrant that resulted in Lisi's arrest earlier this month on drug charges.

Ford refused to comment about the allegations Thursday and refuses to resign, but a handful of councillors and newspaper editorials are calling on him to step down.

A Toronto police press release alleges Lisi, who is also known as Alessandro or Sandro, "made extortive efforts to retrieve a recording."

Ford has 'no reason to resign'

CBC News investigative reporter Dave Seglins said it's believed the charges are related to Lisi's efforts to obtain the video, but expects more will be revealed at Friday's court appearance.

"The question is: Who was [Lisi allegedly] extorting and for what purpose?" said Seglins. "One is left to assume that somehow this is tied to the retrieval of the video."

The surveillance released Thursday also shows Lisi made multiple text messages and phone calls to Mohamed Siad, identified by police reports as one of the people they believed tried to sell the alleged crack video.

Despite calls for his resignation, nothing revealed in the current scandal enveloping Ford can automatically force him from office.

Toronto police Chief Bill Blair said there's nothing on the tape to justify criminal charges and a sitting mayor can only be ousted for missing three consecutive council meetings.

Ford, who was elected to a four-year term in 2010, has said he "has no reason to resign" and plans to run again in next October's provincial election.

"Ultimately this may wind up being a decision for Toronto voters," said Seglins.