The mother of a girl indecently assaulted in her bedroom by a gym instructor is outraged a judge believes there is no evidence the offending was sexually motivated.

The gym instructor, Ross Madden, maintains he was being "playful" when he crept into the girl's bedroom three times, removed some of her clothing, and touched her partially naked body.

Madden, 35, from Otumoetai, who pleaded guilty to a charge of indecent assault on a female under 12, was on Tuesday sentenced in the Tauranga District Court to 12 months' home detention, 200 hours of community work and ordered to pay $5000 reparation.

The crime happened last year while he was babysitting.


But the victim's mother is furious Judge Thomas Ingram said during sentencing he was not satisfied there was "compelling, objective" evidence Madden's conduct had been sexually motivated.

Outside court, the mother told NZME: "I was absolutely shocked that any judge would make this type of comment. My husband is livid."

In court, Crown prosecutor Richard Jenson argued prison was the right outcome given the serious nature of Madden's crime and his attempt to downplay his actions.

Madden had described his offending as "just being playful", but the Crown argued his conduct was for his sexual gratification.

Jenson submitted Madden's name should be added to the Sex Offenders' Register.

Madden's lawyer, Tony Balme, argued home detention was appropriate given this was not a "sufficiently serious" case to warrant a prison sentence.

There was no evidence Madden's actions were sexually motivated and placing his name on the register would be an "excessive" response, he said.

Madden, a first-time offender before the courts, had offered to pay $5000 reparation to the victim, which had been accepted, Balme said.

Judge Ingram said the circumstances of Madden's offending were "most unusual" and he could not recall a case of this kind during his time on the bench.

"The Crown says this cannot be anything other than sexually motivated for you. But I am not persuaded your motivation was sexual gratification nor would it be right to speculate on my part to attribute motivation.

"There is no compelling objective evidence to do so," he said.

Judge Ingram sentenced Madden to the maximum 12 months' home detention.