A 36-year-old man is likely to be charged in connection with the disappearance of Cleo Smith later today, Australian police say.
The four-year-old girl, who went missing from an outback campsite last month, was eventually found safe in a locked house after 18 days.
The Daily Mail reported the suspect sustained a head injury while in custody.
"There is still a lot of work to do ... the investigation continues," said Western Australia state Police Detective Superintendent Rod Wilde.
Cleo was last seen in her family's tent in the early hours of October 16 at the remote Blowholes Shacks campsite in Macleod. An extensive 18-day search involving land and air crews, roadblocks and CCTV footage followed.
She was eventually found safe early on Wednesday when police broke into a house in Carnarvon, a town about 100 kilometres south of the campsite on the far north-west coast of the state.
The house is just three kilometres from Cleo’s family home.
Police on Thursday released an audio recording of when they entered the house and found Cleo in one of the rooms.
"We've got her. We've got her," an officer could be heard saying.
State Premier Mark McGowan said Cleo is a "very bright, upbeat, sweet little girl" and after meeting her family looked "very well adjusted" considering the ordeal.