Teachers at a Nottinghamshire secondary could face prosecution or the sack after an investigation into whether they ignored bullying at their school.
A team from the local authority, including an educational psychologist and a behavioural support officer, spent two days this week at Holgate comprehensive, Hucknall, interviewing headteacher Robert Kenney, teachers and pupils.
Mr Kenney has already resigned from the school after rejecting the conclusions of an Office for Standards in Education report which led to it being put in special measures, in November.
Inspectors said pupils' exam performance was unacceptable and that teachers failed to "create an ethos that inspires children to learn", leading to misbehaviour.
In a letter to parents, Mr Kenney said the school is "much stronger than the picture painted in the report".
However, Holgate has been the subject of a number of alleged bullying incidents. Two years ago, a parent threatened to sue the school, claiming that teachers failed to protect her son from teenage yobs.
The boy, who was on the special needs register, was tied up and beaten by pupils, it was alleged.
Earlier this month, 30 parents said they were considering removing their children from Holgate unless the school cracked down on bullying.
It followed an incident in November when a girl was slapped and punched by a fellow pupil.
Now Nottinghamshire county council is to interview parents, and judge whether staff have been negligent.
John Slater, the council's assistant education director, said: "If the evidence shows a child's interests were being ignored, we could recommend disciplinary action against any member of staff. One or two of the allegations are at the extreme end of the scale and you do not expect that to be happening in school."
A county council spokeswoman said: "It may be that matters could be referred to the police."
A report will be presented to governors by the end of term.
Mr Kenney, who leaves in the summer, refused to comment, although he said in his resignation letter:
"I have found it very difficult to reconcile the Ofsted report judgement on the school."
An executive head from a neighbouring school will take over at Holgate for 12 months.