Obiyo Chigozie Nwigwe, 44, was convicted and sentenced at the County Court in Ballarat on Thursday to six years and six months in prison, and will be eligible for parole in four years and three months.

Had he not pleaded guilty, Judge David Sexton said the total would be eight years and six months, with a non-parole period of six years.

Nwigwe, formerly a doctor at the Bendigo hospital, pleaded guilty to five charges - four of sexual penetration of a child under 16, and one of using a carriage service to transmit indecent images to a child under 16.

He will be placed on the sexual offenders registry for life, and Judge Sexton noted after serving his sentence, he may be deported.

In his sentencing remarks, Judge Sexton described the offending as "extremely serious", with a "catastrophic" effect on the victim and their family.

Nwigwe had met the victim after moving to Ballarat in 2019, before the offending occurred in March 2020 - according to the indictment, in a 15-day period in early March, he sexually penetrated the victim several times at his home in Ballarat.

Two of the charges relate to separate incidents on the same day, which occurred while Nwigwe's own children were in the same house.

The carriage service offence relates to Nwigwe sending naked photos of himself to the victim.

Almost 1000 messages were exchanged between the victim and Nwigwe.

The victim and her family went to police in April 2020, after the offending had ceased, and Nwigwe initially denied the charges in a police interview, the court was told.

However, he had earlier mentioned the offending to his pastor, and eventually pleaded guilty to all charges.

Judge Sexton noted the victim and her parents displayed "integrity and courage" in reading harrowing victim impact statements to the court prior to sentencing.

"Nothing I can say can do justice to the depth of pain and suffering exhibited by (the victim) and their parents in their victim impact statements," he said.

"It is clear from the victim's statement that the impacts of your offending on her have been catastrophic, and have touched virtually all aspects of her life.

"(The victim's mother) spoke of trust placed in you by parents and complete betrayal of that trust by sexually abusing (the victim) on multiple occasions.

"In return for their kindness, you have devastated and ruined the family and taken away their lives as they knew it.

"(Her father) spoke of his pain and distress, and spoke of his failings as a father to protect his daughter, referring to it as a parent's worst nightmare.

"You betrayed their trust spectacularly."

Judge Sexton took Nwigwe's early guilty plea and remorse into account for his sentencing, as well as his "previous good character" and psychiatric reports, but dismissed the idea that undiagnosed depression and post-traumatic stress disorder mitigated moral culpability.

"Members of the community must know that when encountering circumstances of emotional turmoil does not in any way excuse sexual offending such as yours," he said.

"As a result of your offending, you have lost your career as a doctor, you have lost your marriage and likely much trust and respect of your community and family.

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"The law imposes an absolute prohibition on sexual contact with children, and adults transgressing this prohibition must expect stern punishment.

"You were a medical doctor working in the emergency department of the Bendigo hospital - the community rightly expects the highest standards of behaviour in the medical profession."

The standard sentence for sexual penetration of a child is six years' imprisonment and the maximum sentence is 15 years.

Affected by this story? There is help available.

You can phone the Ballarat Centre Against Sexual Assault, in Sebastopol, on 5320 3933, or free-call the crisis care line 24 hours on 1800 806 292.

Or phone Lifeline on 13 11 14, the Blue Knot Foundation on 1300 657 380, or Relationships Australia on 1300 364 277.

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