An attorney who used DNA testing in a 2001 pro bono case to help exonerate two prison inmates convicted of murdering and raping a medical student is now battling the men’s new attorneys for fees she says she is owed.

Kathleen Zellner of Chicago argued in a federal court filing this week that her pro bono work pertained only to the DNA testing motion in the case and that her two clients signed contracts in 2002 agreeing to pay her 40 percent of any recovery they might receive in the future from civil lawsuits for the wrongful conviction.