More young people are reporting mistreatment by Victoria Police.
The number of complaints made by young offenders increased because they are now asked about their treatment under changes to the interview and assessment process, Victoria Police confirmed.
One recent case includes a boy repeatedly bitten by a police dog, Fairfax Media reports.
Victorian Premier Daniel Andrews and Victoria Police would not comment on specific cases.
However, Mr Andrews said anyone who felt they had been badly treated by police should file a complaint.
"Every case should be dealt with on its merits, every case should be properly and fully investigated but it is a matter of fact that we've changed some of the standard operating procedures," the premier told reporters on Sunday.
"If there is anyone doing the wrong thing there should be an investigation."
Police are working with the youth justice system and Department of Health and Human Services to ensure accurate reporting and investigation of complaints, a spokeswoman said.
"We know that many young offenders are vulnerable and at high risk of being victims of crime themselves," she said.
"We are therefore focused on reducing youth offending through an emphasis on early intervention and diversion from the criminal justice system."
