A Canberra man who raped his own daughter during custody visits has been jailed for an extra three years after the ACT Court of Appeal found his original sentence was "manifestly inadequate".
The man was last year sentenced to 12 years in jail after he pleaded guilty to sexually assaulting his daughter from when she was eight years old until she was 14.
That sentence has now been increased to 15 years after an appeal by prosecutors.
ACT Chief Justice Lucy McCallum noted the offender's sexualisation of his relationship with his daughter from such a tender age had had a devastating impact on her.
"She has self-harmed and at times been suicidal," Chief Justice McCallum said.
"She remains extremely vulnerable.
"She will require long-term treatment for her mental health and will probably never recover completely from her traumatic childhood."
The court previously heard that most of the assaults had occurred when the girl had to share a bed with her father when he lived in a share house.
In adding to the man's sentence on Wednesday, Chief Justice McCallum labelled the man's behaviour as "depraved and premeditated" — something she said the man had recognised, pointing to his admissions to police.
"You know, to do this to my own daughter is horrible," the man had told police.
"I couldn't believe where I'd go sometimes ... it just got out of hand.
"I just kept doing it and it just kept intensifying."
'Condemned her to a life of psychological suffering'
The court also heard there had been a couple of "frights along the way" when the man's offending was nearly discovered.
The girl's school had asked questions about her worrying behaviour, and then her mother asked her directly after seeing damning messages on her phone when she was 11 or 12.
The victim denied it.
Her father had later told her she was a good girl and offered to buy her whatever she wanted, as the offending occurred for another 18 months.
Chief Justice McCallum said the original sentence was "unjust" and the appeal should be allowed.
"He of all people ought to have been ensuring that he nurtured and protected her," Chief Justice McCallum said.
"Instead of doing that, he repeatedly traumatised her over a period of eight years and condemned her to a life of psychological suffering."
A new non-parole period was also been set for nine years and four months.
He will not be eligible for release until November 2030.
