A forensic examiner's report stated attorneys hired by Republican lawmakers to assist with the redistricting process withheld 34 emails to groups suing them despite court orders.
The report highlights that lawyers with Michael Best & Friedrich didn't provide subpoenaed documents even after the judges charged them some $17,500 for filing frivolous motions to try to block the release of other records.
The emails cover the methods Republicans used last year to draw new legislative and congressional maps that will help them in elections for the next decade.
The report was filed Monday as required by a panel of three federal judges.
The Milwaukee Journal Sentinel reported a group of Democrats and the immigrant rights group Voces de la Frontera sued over the maps.