Shutting a child alone in a room in school should be banned immediately, MLAs have heard.
That is according to Rachel Hogan from the Children's Law Centre (CLC).
Ms Hogan gave evidence to Stormont's Education Committee into pupils being restrained or put in isolation in schools.
A written submission from the CLC said that "seclusion should never be used as an intervention in an education setting".
The DUP MLA, Peter Martin, said there were some "extremely harrowing examples" of what had happened in Northern Ireland.
"The majority of these cases are occurring in relation to children with disabilities, often non-verbal young boys," Ms Hogan had said.
"It's so draconian, it's not the way we do things today," she later continued.
"There has been a significant delay in bringing forward promised changes."
Ms Hogan said that it had been parents who had "dragged this difficulty into the light".
Deirdre Shakespeare's son Harry was "restrained unnecessarily" in a chair in his school, a report by the public services watchdog previously found.
The Public Services Ombudsman, Margaret Kelly, later told MLAs that her investigation found that Harry had been subject to a level of restraint that "caused real distress".
Mrs Shakespeare and some other parents have campaigned for "Harry's Law" to make it compulsory for schools to report when they have isolated or restrained a child.
"Restrictive practices can be harmful and that harm can be long term and lasting," Ms Hogan said.
In 2023, the Department of Education (DE) published draft guidance, saying restraint and seclusion should only be used as a last resort, after calls for tougher laws on when a child could be physically restrained in school.
But new laws have not yet been introduced.
The committee's deputy chair, Sinn Féin MLA Pat Sheehan, said MLAs had previously heard of a child with autism who "had his hands tied to the chair with a schoolbag."
"And more recently, we heard of a child being tethered to a fence," he continued.
"And his parents were totally unaware of that until they received the child's yearbook and there were photographs."
"I can't even begin to process that, that is very shocking," Ms Hogan replied.
Ms Hogan said that although DE had done a lot of work "there has been a significant delay in bringing forward promised changes".
"How are we going to fix this if we don't reform the legislation that talks about force?" she asked.
"We need to make it easy for school leaders to know what to do.
"You should never use force in order to maintain discipline, particularly in relation to a disabled child.
"Use of any force to maintain order and discipline is just a whisker away from when we used to hit people at school, frankly."
Ms Hogan said that there was provision law for school staff to intervene if there was risk of "serious harm" to a pupil or member of staff.
She said that teachers and school leaders should be thanked "for the difficult decisions they make every day".
Ms Hogan also told MLAs that part of the difficulty was that the Education Authority (EA) was providing "inappropriate placements" in school for some children.
"A school has maybe said 'we can't meet the needs of this child,' and they're being placed anyway," she said.
In March, the Royal College of Nursing (RCN) resigned from a taskforce set up by the department to look at the use of restraint and seclusion in schools.
The RCN expressed serious concerns over the direction of travel by DE on the issue.
The Department of Health had previously instructed that children and young people should never be shut in a room alone and prevented from leaving.
Paris Hilton has previously backed parents trying to toughen the law on restraint and seclusion in Northern Ireland's schools.
The businesswoman has said she was placed in solitary confinement when at boarding school in the US as a teenager.