Warren, a Democrat locked in a battle with Sen. Scott Brown, R-Mass., was listed as a minority at the University of Pennsylvania Law School in addition to her listing as a minority professor at Harvard University where she is on faculty, an April 2005 document obtained by The Hill indicated.
The revelation a second school listed Warren as a minority raised more questions about her claim of American-Indian heritage, The Hill reported Thursday.
Warren hasn't been able to independently authenticate her claim to the heritage and does not claim tribal membership. A genealogist told the Boston Herald Warren's great-great-great-grandmother may have been Cherokee, which would make Warren 1/32 Native American.
"At every law school where Elizabeth was recruited to teach, it has been made absolutely clear she was hired based on merit, on her accomplishments and ability," Warren spokeswoman Alethea Harney said. "Documents from the college and law school from which she graduated show that Elizabeth did not seek special treatment by acknowledging her Native American heritage."
Brown's campaign is among those who have questioned whether Warren used the claim to advance her career, which Warren has denied.
Warren said she didn't know Harvard named her as a minority when promoting faculty diversity. She also said she never mentioned her heritage when seeking employment.
In a University of Pennsylvania "minority equity report," published in April 2005, Warren's listing indicated she was a minority.
Brown's campaign has called on Warren to "come clean" about the listings.
"As candidates for high public office, we have a duty to be transparent and open and not hide behind a wall of silence in the midst of public controversy," Brown said.