ITV News Tyne Tees has obtained secret footage which shows teachers making physical threats towards a pupil, at a school for children excluded from mainstream education.
Durham County Council says that it has investigated and taken action over staff behaviour at The Woodlands pupil referral unit in Ferryhill.
The filming, carried out by a 14-year-old boy at the unit early in 2016, also shows a teacher swearing at the pupil, and a member of staff appearing to boast about how best to sell drugs.
The case has now been referred to the national organisation that regulates teachers' conduct.
Watch our exclusive report:
The Woodlands pupil referral unit is run by Durham County Council, for children who have been excluded or are at risk of permanent exclusion from school.
The footage was filmed in April this year, by a 14-year-old boy, whose family were concerned about how he was being treated.
Durham Police have reviewed all of the footage, and found no criminal acts, or safeguarding concerns.
A child psychiatrist in the North East, with more than a decade of experience treating young people with emotional and behavioural disorders, says the footage shows inappropriate behaviour from staff.
Question marks around staff conduct also surfaced in 2012, at the same unit - then known as Broom Cottages Pupil Referral Unit.
13 members of staff were suspended over allegations around the use of force towards pupils.
Nobody was prosecuted, but the council held its own investigation and made the following recommendations:
- that the child protection policy... is reviewed urgently and is fit for purpose
- urgently review the code of conduct for staff so that all are absolutely clear of the staff behaviour that is expected
- making it clear that staff will not swear at or in front of students
After reviewing the footage filmed by the 14-year-old pupil this year, Durham County Council has told us it has taken action to reinforce the standards expected of staff.
The family have referred their concerns to the regulators, the National College for Teaching and Leadership, who will have to decide whether any of the teachers at The Woodlands should face a hearing for serious misconduct.
Ofsted also carried out a routine inspection of the pupil referral unit in June, and is due to publish its report on standards there in the next few weeks.