Fifteen summer school students have been expelled for cheating at Montana Tech, the same college that dismissed several Saudi students and revoked the degrees of others after discovering a former employee altered their transcripts four years ago.

Doug Abbott, vice chancellor for academic affairs, declined to release any other information about the 15 students, including how they cheated, if it was a coordinated effort or if they were international students.

"Montana Tech has high academic standards, and we take academic dishonesty very seriously," he told The Montana Standard newspaper Wednesday. "I think the permanent dismissal of these 15 students is evidence of the quality education that we give at Montana Tech."

The school's website says academic dishonesty includes plagiarism, helping another student or copying from another student while taking a test, and using unauthorized aids to pass an exam.

Abbott characterized the cheating and expulsions as a one-time incident at the small, four-year college in the mining city of Butte. It is known for its metallurgy, mining and engineering specialties.

Scores of Saudi students, many of them sponsored by their embassy's cultural section or the Saudi Arabian Oil Co., attend Montana Tech every year to study for degrees in fields such as petroleum engineering.

In January 2012, the school said a former employee had made hundreds of alterations to the transcripts of 36 students by changing grades, giving them grades for courses they didn't take and deleting some grades, apparently in exchange for small gifts.

Saudi Embassy memos published by WikiLeaks revealed, and school officials confirmed, 33 of the students were Saudis and their government booked flights home for them after a meeting between college administrators and Saudi diplomats.

The meeting in Washington, D.C., occurred before the transcript alterations became public. At the time, Abbott said the college had been advised by legal counsel that the Saudi Embassy should be informed.

Seven of the 36 students were allowed to return to college, including two who said their grades were changed without their knowledge, according to the Saudi memos. It's not clear how many degrees were revoked.