AN angry mum claims her 15-year-old daughter was threatened with suspension from North Rockhampton High School for using the toilet in class time.

The mother said yesterday her daughter asked the teacher while in class last week if she could go to the toilet and was refused permission.

When she got up to go without the teacher's permission, she was placed on detention.

After being told what had unfolded, the mother said she instructed her daughter not to complete the detention, labelling it "ridiculous".

"It sounds ridiculous to me.

"They were threatening her with suspension for going to the toilet during class," said the mum, who The Bulletin has not identified.

"She's a 15-year-old girl - I could not believe the stupidity in it."

On Friday, the daughter was suspended from the school for an unrelated incident.

The mother said a number of students were caught taking drugs on school grounds.

She said her daughter was with the group but was not using the substances.

But she still copped a 10-day suspension.

Her mum believes the suspension was the result of her advising her daughter not to do the detention.

"It was a totally different incident, but we believe she was given the harshest treatment because of what's happened in the past."

A police spokesman confirmed one student at the school had been interviewed regarding the incident, but no-one had been charged.

He said the students were disciplined through the education system.

The mother said she had contacted the Department of Education, Training and Employment, which was conducting an investigation.

Rockhampton Region Disciplinary Absences 2012*

* Statistics found in DETE School Disciplinary Absences by School table