The parents of some pupils at the Boitsanape Technical School in Mafikeng have sought the intervention of the province's public protector's office after their children, who had initially passed, were demoted by the North West department of education.
This emerged when some of the pupils who failed reportedly attempted suicide.
Initially more than 20 pupils had passed Grade 9 but the department allegedly issued new reports that said they had in fact failed, parents said.
The angry parents went to the public protector's office after a meeting with education officials yielded no positive result.
Paballo Moseki, an investigator in the public watchdog's office, told Sowetan that parents had complained about the school but he declined to reveal details.
Segopolo Mokgobe, whose child was affected by the results, said the incompetence of the department had led to some pupils attempting suicide.
"One girl is still at Bophelong Hospital after swallowing a lot of pills last Friday," Mokgobe said.
"Our children spent their holidays thinking they had passed. What the department has done is inhuman."
A pupil who refused to be named said: "Some of our classmates have used their original reports to be admitted to other schools. We will do the same."
Education spokesman Charles Raseala said teachers at Boitsanape had made a mistake by issuing the results before the circuit office had signed them off.
"We had a meeting with parents last Thursday at which we explained the situation. We will deal with the principal and teachers," Raseala said.