A political-science professor at the University of California at Los Angeles, who says he suspects that his institution is “cheating on admissions” by illegally taking into account the race of student applicants, has resigned from a university admissions committee in protest.

The professor, Tim Groseclose, who has made his suspicions public in a report he posted on his UCLA Web site, says high-ranking administrators at the university and members of the committee are “engaged in a cover up” by refusing to allow him access to data about applicants so he can investigate his concerns. He says that the university’s new “holistic” approach to evaluating students allows it to let the race of applicants carry more weight than is allowed under a constitutional amendment that California voters adopted in 1996. The percentage of black students admitted as freshmen rose sharply after the new admissions policy was adopted, in 2006.

According to the Los Angeles Times, the number of entering black students edged up this fall, to 230 out of of 4,889 freshmen. In 2006, 103 black students entered as freshmen. University officials said Mr. Groseclose’s conclusions that race-conscious admissions policies played a factor failed to take into account the higher level of recruiting that the university has undertaken since then.

The study is likely to add fuel to the continuing debate over affirmative action in college admissions. Ward Connerly, the Californian whose activism first led to California’s 1996 ban on the use of race in admission and whose American Civil Rights Institute is seeking to propose similar bans through ballot questions in three states this November, told the Times that the study might become grounds for a lawsuit against the university.

Mr. Groseclose has been in the eye of a news-media storm before. In 2005 he was an author of a widely quoted paper that suggested most major media organizations had a liberal bias. —Goldie Blumenstyk