Victoria's Victims of Crime Commissioner and politicians on both sides of Parliament have welcomed a High Court ruling that has effectively found that the Court of Appeal should have increased the sentence given to a man for sexually abusing his stepdaughter from the age of nine.

The court has ruled that current sentencing practices, or the sentences handed down in similar cases, are one factor to be considered in a judge's decision making, but not the controlling factor.

The Commissioner Greg Davies says it sends a message that sentences have been too lenient, and he's hopeful of change.