Terence Kelly has pleaded guilty to the abduction of four-year-old Cleo Smith from a Western Australia campsite.
Kelly admitted his guilt when he appeared in Carnarvon Magistrates Court on Monday morning via video link from the maximum-security Casuarina Prison in Perth.
Kelly's grandmother Esther Mingo attended the hearing and told reporters she wanted the "truth" to emerge.
"I'm upset, I'm angry for him coming to court," she said, ABC News reports.
Kelly's case will now be transferred to the district court in Perth, where a date may be set for his sentencing.
Cleo vanished while on a family camping trip in the outback for 18 days.
Police received a tip leading them to Kelly's house in Carnarvon - a town about 100km south of the campsite she vanished from - where they found Cleo in a bedroom in the early hours of November 3, 2021.
"Cleo is alive and well. A police team broke their way into a locked house in Carnarvon about 1am," deputy Western Australia Police Commissioner Col Blanch said at the time.
"They found little Cleo in one of the rooms."
Social media posts showed Kelly posing with Bratz dolls with one photo featuring a room full of dolls and toys.
When Kelly first appeared in court in November he expressed anger at the media, at one point looking at them before swearing and saying "I'm coming for you" and "why are they here?".
