A "delusional" Canberra rapist has had three years added to the jail sentence imposed on him after he admitted sexually assaulting his own daughter dozens of times over several years.
Chief Justice Lucy McCallum described the original 12-year term as "unjust" on Wednesday, when she and two of her fellow ACT Court of Appeal judges re-sentenced the offender to 15 years behind bars.
The 38-year-old offender's non-parole period, which had initially been set at seven-and-a-half years, was increased to nine years and four months.
When the man was first sentenced in February, the ACT Supreme Court heard he had regularly raped his daughter between 2013 and 2021.
The girl was aged between six and 14 during the offending.
Acting Justice Stephen Norrish, who imposed the original sentence, said the offender seemed to have "some deluded belief" the child had enjoyed the depraved incidents.
One occasion of abuse involved the man angrily raping the crying victim, who was 11 at the time, to punish her after she had jumped on his bed.
Following his arrest, the offender pleaded guilty to a charge of maintaining a sexual relationship with a child under special care. He faced a maximum penalty of 25 years in jail.
Acting Justice Norrish found 16 years in jail to be an appropriate starting point, knocking off 25 per cent in recognition of the man's plea and arriving at the initial 12-year sentence.
ACT Director of Public Prosecutions Shane Drumgold SC appealed, arguing this starting point was too low when Acting Justice Norrish had described the crime as almost the worst case scenario for an offence of its type.
After about a month considering the appeal, Chief Justice McCallum, Justice Michael Elkaim and Justice Berna Collier unanimously upheld it on Wednesday.
Chief Justice McCallum said the victim had "suffered dreadfully" as a result of the abuse.
As she concluded that the appeal should be allowed, the ACT's top judge added that the girl would "probably never recover completely from her traumatic childhood".
"In short, the offender repeatedly raped his young daughter over many years at a time when 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."
Justice Elkaim said he agreed with Chief Justice McCallum's reasoning, adding that there could be "little argument that the sentence was disproportionate to the offending".
Justice Collier, who read both the other judges' decisions in draft form, agreed with them.
Under the terms of the new sentence, which was backdated to the offender's arrest in July last year, the 38-year-old will not become eligible for parole until November 2030.
Wednesday's decision marks the latest appeal success for Mr Drumgold, who has been challenging a record number of sentences he believes have fallen "clearly short of community standards".
As The Canberra Times revealed last week, the ACT's top prosecutor has mainly focused his office's appeal efforts on sentences dished out to murderers and child sex offenders.
