50 Students Accused of Altering Grades at High School in Arizona Implicated seniors will not be allowed to graduate until they retake the class.

 -- About 50 students at a high school in Arizona have been accused of tampering with grades in what the school district's superintendent called the largest cheating ring at the school in recent memory.

The majority of the 50 implicated students at Tucson Magnet High School are seniors and they will not be allowed to walk at graduation next week, Tucson Unified School District Superintendent H.T. Sánchez told ABC affiliate KGUN on Wednesday.

"The students are facing the ultimate consequence," Sánchez said. "Their parents may have sent out graduation invitations, they're planning parties, but the students will not graduate. They have to take the class, they have to pass it the right way."

All students implicated in the "grade-changing scheme" will "have to retake a required course to earn credit for it," the school district wrote in a statement online. "For those who are seniors, graduation will be delayed until credits are completed. It will be offered as an in-person class during the summer."

The school district's investigation found "that a few students had learned the teacher's password and then began charging a fee to manipulate grades for other students," the district said in the statement. It added that its technology services department is working to require teachers to change passwords more frequently to "help prevent a reoccurrence."

Sánchez added in the statement that the acts of the few should not overshadow the achievements of the many.

"We have 3,000 students at Tucson High, and on Wednesday [May 25], hundreds will be walking across the stage to accept the diplomas they earned through hard work and perseverance," he said. "The bad decision of one group of students does not reflect on Tucson High, which is a great school, or the thousands of others who striving for academic excellence every day."