Children in state care are engaging in "late-night group sex", "pre-planned sex romps" and raping of younger children in two residential care homes in west and north Melbourne.

In a supposedly classified government report, harrowing accounts of sexual activities by young children in home cares were exposed. Children as young as nine years old engaged in "late-night group sex." One boy at the age of 12 raped a boy aged 9 while they were on a hammock. There were also four children ages between 9 and 12 that participated in "pre-planned sex romps" while three children, ages 11, escaped the home care, had sex with each other and came back after two hours.

These tormenting details of sexual acts of children were all accounted in a secret government report obtained by Herald Sun.

The Department of Human Services is currently being asked to explain why it kept information of children with sexual history hidden from staff at home care. These children should have been placed in separate care away from other children.

According to home care staff interviewed by the newspaper, DHS had also kept mum regarding an investigation being conducted on a rape case against a boy who abused a 10-year-old girl.

"They chose not to tell us because they knew we would have pushed back. It's happened lots of times before where there have been substantiated allegations, but not a police investigation before. The greatest need is to get a bed, regardless if the kid is a survivor, a perpetrator or a victim," the staff told Herald Sun.

Jenny Mikakos, Opposition spokeswoman for community services, said that overnight security for the care facilities should be enhanced to prevent further incidents.

For Minister of Community Services Mary Wooldridge the expose' was "distressing and devastating for all those involved."

Apparently, DHS had been alerted previously and funding had been increased for the department to pay extra staffing at night. However, it seemed that DHS was not doing what was expected of the department.

"Immediately after DHS was alerted, additional funding for extra staff was provided to the community sector organisation," Wooldridge told Herald Sun.