Records show that potential Democratic candidate for governor Mary Burke paid nearly $517,000 in Wisconsin income taxes the past five years.
The Milwaukee Journal Sentinel first reported on the tax information as provided by the state Department of Revenue.
Burke is exploring a run against Gov. Scott Walker next year but has not officially gotten into the race.
Based on the amount of taxes she paid, Burke would have had to report an adjusted gross income of at least $6.8 million from 2008 to 2012.
Republicans have tried to paint Burke as an out-of-touch liberal millionaire.
Burke's father started Trek Bicycle Corp. and she formerly worked for the company but has since retired and is now on the Madison school board.