Updated

The publisher of the graduate business school entrance test said Wednesday it has thrown out the scores of 84 prospective students after shutting down a Web site they used to cheat on the exam.

The Graduate Management Admission Council said it had notified 84 people about the cancellation of their scores from the Graduate Management Admission Test. More than 500 scores were tossed, as test-takers could take the GMAT several times, and many of the test-takers sent scores to more than one school.

The council began tracking down users of Scoretop.com after winning $2.35 million in a copyright-infringement lawsuit in June, which allowed the council to shut down the site and seize a computer hard drive containing payment information and users' identifications.

The council said an investigation of 6,000 scores from 2004 to 2007 found that 12 people posted questions from the exam on Scoretop. Those people will be barred from retaking the test for at least three years.

The other 72 posted messages on Scoretop confirming that they saw items from the site on their GMAT exams. Those test-takers will be allowed to retake the exam, council spokeswoman Judy Phair said.

"We take the action of canceling scores very seriously, with a full understanding of our ethical responsibility to both students and schools to protect the integrity of the test and the application process," GMAC President David A. Wilson said in a statement.

GMAC acknowledged it had to take a cautious approach, making certain that it could positively identify cheaters before throwing out their scores, and Phair said some violators "are fortunate that we weren't able to do a match on them."

GMAC also sent out notices to more than 100 business schools that received those students' test scores, but Phair said she wasn't allowed to disclose which schools were contacted. GMAC doesn't track where students are accepted or rejected, or even whether they applied.

Phair said GMAC notified the students by e-mail Friday and the GMAC received "a lot of calls from students Monday morning."

Scoretop had sold VIP access for $30 a month, and premium users could preview current questions on the latest GMAT, some posted by users after taking the exam. In court documents, GMAC cited a comment on Scoretop.com by a user who said the value of the test information on the site was "inestimable."

The council's decision to cancel scores came after investigators matched data found on Scoretop against GMAT registration records and test information. While officials aren't expanding the investigation, GMAC could investigate any subsequent information about Scoretop use and "take appropriate action," Wilson said.

About 200,000 students take the GMAT each year, and its scores are used by more than 4,000 graduate management programs at 1,800 business schools worldwide, GMAC said. Test-takers must sigh a no-cheating pledge when registering for and when taking the test.