Leading human rights and child welfare experts have slammed the "shocking" scene of a grown man allegedly keeping Aboriginal children as young as six detained by tying them with zip-ties.

The video and images emerged on Tuesday, shortly after the incident.

45-year-old Broome resident Mat Radelic has been charged with three counts of aggravated assault and will appear in court on March 25.

Noongar academic and human rights law expert Dr Hannah McGlade told National Indigenous Times that the "shocking incident has shown the ugly face of racism in Western Australia".

"Young Aboriginal children crying and tied up in a vigilante style manner. I hope the police use their power under the Criminal Code WA to ensure the racist element is reflected in the law," she said.

"Race motivated crimes are required to be prosecuted as such under the binding international treaty the Convention on the Elimination of Race Discrimination.

"I call on Minister Tony Buti and the Premier Roger Cook to take serious efforts to stamp out racism in this state. The Equal Opportunity Commission has failed Aboriginal people and we have never seen a serious investment into addressing racism.

"We know that racism against Aboriginal children is prevalent and can even result in children being assaulted, possibly even killed on our streets. Section 801 of the Criminal Code addresses crimes that include racial aggravation and this crime certainly does evidence such behavior, it should be used so that people inclined to assault Aboriginal children understand the full consequences of their actions."

Dr McGlade noted that the children were reportedly swimming in a backyard pool.

"Why don't we, in this current cost of living crisis, open the public swim pools free of charge so all children can enjoy them? We know swimming is really good for children's health. If we're serious about addressing youth offending we need to make sure that all children can have equal opportunity for play and fun," she said.

WA's Commissioner for Children and Young People WA, Jacqueline McGowan-Jones, was "appalled at "media reports of young children being cable tied by a tradesman in Broome yesterday".

She noted that a distressed passer-by live-streamed the incident over a fence as they pleaded with the man to release the trio, who were crying.

"The video footage was extremely confronting; the children appear quite frightened and nervous," the Commissioner said.

"It is my understanding that the children were swimming in the pool of the vacant house and while full details are not yet available about why the police were called, we need to understand that these are young children and there is absolutely no excuse for such an overreaction.

"These children are aged six to eight and international research shows at that age – whether they have a disability, cognitive impairment or not – children are not able to fully comprehend the moral consequences of their actions.

"The police did the right thing calling St John Ambulance and investigating further... We also need a system that is going better support prevention and early intervention to stop having children and young people wandering the streets."

Commissioner McGowan-Jones said she was contacted by multiple community members on Tuesday "about this distressing incident".

"People are worried about the children, about possible vigilante action, and I would just like to encourage the community to remain calm in the wake of this alleged assault," she said.

"I am also calling on the government to develop a holistic child and family wellbeing strategy to ensure early intervention for our most vulnerable children."