The Chicago Tribune is suing Mayor Rahm Emanuel over claims he violated open records laws for failing to disclose personal emails and texts used to conduct city business.
Thursday's lawsuit asks a judge to force the former White House chief of staff to produce documents.
The lawsuit argues that the newspaper's Freedom of Information Act requests to Emanuel's administration have been "met with a pattern of non-compliance, partial compliance, delay and obfuscation."
Chicago Tribune Editor Gerould Kern says in a statement that the newspaper is seeking public records on matters of great public interest.
Emanuel's spokeswoman declined comment.
The issue of public officials relying on personal email for official business has come in the spotlight. Presidential candidate Hillary Clinton faces questions over use of a private account and server.
Earlier this month, Clinton admitted she feels it was a mistake to use her private e-mail account and acknowledged that she could have handled the resulting inquiries more effectively.
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"I do think I could have and should have done a better job answering questions earlier. I really didn't perhaps appreciate the need to do that," she said.
