Nine cases of student cheating on standardized tests were reported statewide during the last school year, the Nevada Department of Education reported.
And four cases of alleged test security violations by teachers were referred to the state attorney general for investigation, up from one case a year earlier.
Two of the four cases were reported at Desert Pines and Western high schools in Clark County, while the others were reported at Sparks High School and Best Elementary in Fallon.
All but the Sparks case involves teachers accused of helping students on tests.
Tom Sargent, a spokesman for the attorney general's office, declined comment on the investigation.
"We don't like to play these things out in the court of public opinion," he told the Reno Gazette-Journal.
Overall, the education department reported 79 testing irregularities statewide in 2002-03, up from 50 the previous school year.
Irregularities can range from power outages and missing test booklets to student misconduct and improper test administration.
Six of the nine cases of student cheating were on the high school proficiency exam, likely because the stakes are higher, said Carol Crothers, assistant director of accountability for the education department.
Students must pass the proficiency exam to get diplomas.
At Spanish Springs High School in Sparks, a student wrote answers to the math portion of the test on a separate sheet of paper, then provided them to another student during a prearranged restroom visit.
Both students were suspended and their tests were invalidated.
Every case involving cheating or other problems is forwarded to the state as required by law, said Dotty Merrill of the Washoe County School District.
"We're very vigilant," Merrill said. "People are paying attention and we're reporting incidents from all our schools."
Robert Voutrin, a student at Reed High School in Sparks, said he's unsure schools can discourage cheating except by invalidating tests.
"That's all they can do," he said. "And get the point across that it's a serious test they need to graduate."