A former Duke University lacrosse player who graduated last year said in a lawsuit filed on Thursday that a professor had flunked him because of accusations of rape that had been made against his team.

Kyle Dowd, who was not charged in the rape case, sued the university as well as Kim F. Curtis, a visiting assistant professor of political science who taught a 40-student “Politics and Literature” course last spring. According to the lawsuit, Mr. Dowd was a C student in the course before the now-notorious spring-break party at which a stripper accused lacrosse players of gang-raping her. (Rape charges against the players were dropped last month, and Duke this week told two of the athletes that they could return to the campus and resume their studies while lesser charges are pending.)

By failing Mr. Dowd, Ms. Curtis “engaged in extreme, outrageous, and unethical conduct … due to personal bias and prejudice,” the lawsuit states.

The professor told the student his F was based on a poor final paper and excessive absences from class, according to the lawsuit, which was filed in Superior Court in Durham, N.C. Mr. Dowd seeks $60,000 in damages and a passing grade on his official transcript.