EVANSTON, Ill. — WGN Investigates has learned that Evanston’s mayor has requested a criminal investigation of the entire city council and several other government employees — raising concerns about politics, privacy and the public’s right to know.

Evanston Mayor Stephen Hagerty has formally asked Cook County Sheriff Tom Dart to open a criminal investigation into the Evanston City Council. The investigation includes eight staff members, and outside attorneys over the leaking of “highly sensitive and confidential information” that the mayor characterized as “official misconduct,” according to a memo to the city council, obtained by WGN investigates.

The mayor declined to comment on camera for this story, saying his letter would speak for itself.

In the letter, he told council members that he asked the Evanston Information Technology Department to turn over data related to sensitive files that only the alderman, mayor, city staff and outside legal counsel had access to as part of an “executive session” to deal with an explosive personnel matter.

The mayor is attempting to track down the person responsible for leaking — and thus violating the privacy rights — of an employee embroiled in a messy disciplinary situation.

A source told WGN Investigates that the leaked documents contained embarrassing content of a sexual nature — including transcripts of recordings in which inappropriate sexual conduct was discussed.

The documents also outlined allegations of harassment against a top elected official — identified by the source as City Clerk Devon Reid.

Tension between the mayor and the clerk flashed in public recently at the June 15 city council meeting where the mayor and the city clerk briefly sparred over whether a member of the public should be heard, or have the microphone cut off.

The mayor said any evidence collected in the investigation will be turned over to the state’s attorney, and the person responsible could be prosecuted.

The mayor said this is an embarrassing episode for the City of Evanston, but the criminal investigation is necessary to rebuild the trust of city residents.