A child protection officer saw a malnourished teenage boy gnawing on a dog bone in a case of abuse and neglect that lays bare government agency failings to protect young people with disabilities, a federal inquiry has heard.

The Disability Royal Commission on Wednesday heard that child protection workers, education officials and police in Queensland had failed to protect the boy and his brother who were left naked in a bedroom with the door handles removed.

The two autistic brothers, then aged 17 and 19, were found in their Brisbane home in May 2020 in soiled nappies, with their father dead in another room when emergency services arrived.

Queensland government agencies had known of risks to the boys, counsel assisting the commission, Kate Eastman, told the Brisbane hearing.

She said the violence, abuse, neglect and deprivation of human rights they experienced at the hands of their father were entirely preventable, pointing to hundreds of complaints and dozens of missed opportunities by officials involved in their care.

“This was a family experiencing poverty, substance abuse, poor mental health and inadequate housing,” Ms Eastman said.

Queensland’s former Department of Child Safety chief Dr Meegan Crawford acknowledged a “considerable amount” of contact was made with the family over a 20-year period including 23 separate child protection matters brought to its attention.

In 2019, a child safety officer observed one of the boys “eating a large raw dog bone” previously gnawed by a dog after a report from a concerned member of the public prompted a visit to the home.

Ms Crawford conceded the incident was “very distressing” but said the department was not legally mandated to intervene and “follow-ups” had occurred.

She said there were “attempts to prevent the abuse by supporting the father” but she accepted she should have done more to stop it.

Commissioner John Ryan said the boys’ conditions “sound like torture to me” and he accused Ms Crawford of coming up with “excuse after excuse”.

The inquiry heard the boys regularly appeared at school needing to be bathed, clothed and fed.

Education department records from 2018 stated one of the boys came to school “smelling of a strong dog odour, passing rocks, pebbles, during bowel movements”.

Hayley Stevenson, Assistant Director-General at the Queensland Department of Education, conceded the school knew the boys were subject to neglect but it was not reported to the Department of Child Services.

“The school took a supportive response, not necessarily a reporting response,” she said.

Ms Eastman noted various police reports regarding concerns for the boys’ care over a 10-year period.

One record from 2010 referred to a school notification they were “showing signs of hunger on a regular basis” and there was concern “bowel motions contained foam rubber, possibly from home lounge or mattresses”.

After the boys’ visit to a camping ground with their father in 2015, one camper filed a crime stoppers report noting they were left unsupervised for most of the day inside a tent in 35-degree Celsius temperatures.

The camper said the youngest boy hid behind someone but the father then “kicked him very hard up the backside” and on another occasion “went into the tent and started smacking him loudly”.

Ms Eastman asked Queensland Police Commander of the Child Abuse and Sexual Crime Group, Detective Superintendent Denzil Clark, whether those claims would constitute assault and he replied that officers would “have to consider domestic discipline”.

“The officer assessed it and made an informed decision not to report it,” the detective said.

The Public Guardian has been appointed for the young men who now have their own bedrooms and around-the-clock disability support in the home they share.

-AAP