Child protection workers are exposing vulnerable children to more risk by leaving them with extended family – often without scrutiny in emergency "drop and run" placements, a secret Department of Health and Human Services report has revealed.

A June 2016 review of the kinship care model, obtained by Fairfax Media under a Freedom of Information request, also showed that department staff were failing to report critical incidents involving child safety. .

Children are placed in out-of-home-care, with foster carers or relatives, if they can not be cared for by their parents.

But Professor Muriel Bamblett, who heads Victorian Aboriginal Child Care Agency, said authorities should not assume that relatives could care for children without any support.

"We often presume that because you are kin, you have all the skills and qualities to look after children, but it is really quite dangerous to think that because you are a relative that you are actually able," Ms Bamblett said.

"The reality is a lot of these carers are very vulnerable, so we do need to be able to support them."

A department spokeswoman said the Victorian government was reforming the out-of-home-care sector to ensure vulnerable children and their carers received the support they needed.

The damning report points the finger at staff, under increasing pressure as demand for kinship placements outstrips foster care, failing carers and children.

According to the report, at November 30, 2015 the number of children placed in kinship care was more than double of out-of-home-care placements. Of the 8308 children in out-of-home-care placements, 4880, or 59 per cent, were in kinship care.

The KPMG findings reveal that child protection workers are failing to identify appropriate kinship carers, conduct assessments or monitor kinship care placements.

One kinship carer has been looking after her granddaughter since 2006

The carer, who can't be named for legal reasons, said when her granddaughter turned four, the kindergarten noticed signs of abuse and symptoms of drug withdrawal and called the department.

But when the grandmother could not be reached, the toddler was left with an aunt.

"There was nothing provided, she was basically just dumped at [my daughter's] doorstep," the grandmother said.

"There was no support. Basically, the child was handed over and that was it. Full stop. Close the door and go away."

After two weeks, the grandmother was forced to step in, but struggled to cope financially.

"DHHS never informed me of my rights to any financial support whatsoever, it was left up to me to do it," she said.

"Basically, DHHS financially abandoned me. I had to go to Centrelink to find out what I was entitled to."

Her experience is not isolated. The report found it was "not uncommon for the kinship carers, who are first identified by child protection practitioners to provide emergency care for a 'few nights' to end up providing care for a number of months or years without child protection practitioners routinely revisiting whether this was the most appropriate placement."

The findings also reveal that 16 per cent of child protection staff surveyed for the report said "assessments were rarely conducted before a placement", while another 25 per cent said assessments were conducted only "sometimes".

Almost 60 per cent of child protection staff surveyed said mandatory annual assessments were not conducted.

The delay or incomplete assessments resulted from the "erroneous assumption" that children in kinship care placements were "safe with family".

"These delays breach DHHS guidelines and are likely to impact on children or young people being placed with suitable carers, supports provided to kinship carers, and/or the stability of a placement," the report stated.

When compared with government-funded community organisations, DHHS staff were likely to under-report critical incidents, with potentially "thousands of critical incidents each year for child protection managed kinship care placements that are not being reported by DHHS".

"This high number of unreported critical incidents is a serious risk for DHHS and for the children and young people in kinship care placements," the report stated.

Grandparents Victoria and Kinship Carers director Anne McLeish said for professionals and carers, the confidence in the kinship care system remained low.

"They are just not paying attention to kinship care.," Ms McLeish said.

"Many carers are given babies and other young children to raise at a very short notice and without any support being offered. We have reports of kinship carers having to borrow money from other family and friends in order to buy the basics such as bottles and nappies that babies need immediately.

"In some cases, it is years before they [the department] go back to see if the carers are coping and whether the children are doing well."

The report also shows that staff did not make a "rigorous" attempt to identify a suitable Aboriginal kinship carer, instead placing the child with a non-Aboriginal family after a "short search".

Many Indigenous carers described the initial placement process as "drop and run".

Staff showed a lack of knowledge of Aboriginal culture, with some reports of them questioning the Aboriginality of carers based on their skin colour.

"DHHS is spending the least on, and providing the least support to, the placement type that is likely to achieve the best short, medium and long term outcomes," the report stated.

A department spokeswoman said "the Victorian government had delivered more financial support to kinship carers in each of the last three budgets and was looking at what further support could be provided as part of its overhaul of the out-of-home-care system".