A VIOLENT man convicted of a series of horrific assaults on a 15-year-old girl he held prisoner has been freed from jail because he is an Aborigine.

The Herald Sun reports the Court of Appeal ruled that participating in a Koori Court, where offenders discuss their crimes with a judge and Aboriginal elders in a room that has been traditionally "smoked", can lead to a lighter sentence.

Court president Justice Chris Maxwell and Justice Peter Buchanan said the 18-month minimum term imposed on Steelie Morgan, 26, was manifestly excessive because he took part in a "sentencing conversation" about his crimes.

"His active participation in the process was a factor that mitigated punishment," the court said.

"The sentencing conversation is designed to further the reformation of an Aboriginal offender through a unique blending of Aboriginal customary law and the English common law."

Morgan has served seven months of the term but the appeal judges said the rest of the sentence should be wholly suspended.

During a 10-week reign of terror Morgan, of Moama, subjected the girl, who was his under-age sexual partner, to a series of attacks, where she was bashed, stabbed, humiliated and held captive.

He threatened to kill her, smashed a full plastic water bottle over her head, threw a knife at her, which struck her on the neck, and bit her nose.

Morgan made a weapon of a water hose and repeatedly struck her on the legs, threw a heavy tool, cutting her head, and forced her to stay in a bedroom for nearly a month.

Morgan pleaded guilty at La Trobe Koori Court to eight counts of causing injury intentionally, two of assault, one of making a threat to kill and one of false imprisonment.

The offences occurred between December 2007 and March 2008 and each count of intentionally causing injury carries a 10-year maximum term.

After he was caught Morgan "sought reconciliation with his indigenous heritage", the court said.

Justices Maxwell and Buchanan said Morgan was shamed by admitting his crimes before Aboriginal elders.