A man accused of murdering his partner's daughter feared he would go back to prison if the girl did not return to Queensland, shortly before she went missing, a jury has heard.
He had earlier been found digging for "treasure" by a neighbour.
"It seemed strange," the neighbour told a court on Wednesday.
Justin Laurens Stein, 33, has pleaded not guilty to the murder of nine-year-old Charlise Mutten in January 2022.
The girl was reported missing from the Mount Wilson property in the Blue Mountains west of Sydney where she was staying with Stein and her mother Kallista Mutten.
The neighbour who came across Stein digging in the bush near their properties after his german shepherd took an interest said it looked like he was hiding, lying face down in a culvert, before he asked Stein what he was doing.
"His answer to me was he was digging for treasure," the neighbour said, telling the court he agreed not to tell anyone.
"I thought it was weird but I didn't think it was dangerous."
Eventually the neighbour did tell police when they showed up looking for Charlise the next month.
The neighbour had previously attended a dinner with his wife and mother-in-law, where Stein, his mother, Charlise and her mother were also present.
He recalled conversation about custody of the girl, who had been living on the Gold Coast before visiting her mother.
"(Stein) said that if anything happened and the child didn't go back to Queensland that he would end up in prison again," the neighbour said.
The jury has heard Stein had been jailed for drug-related offences and was being treated for addiction as well as schizophrenia.
He met Charlise's mother while she was in prison for dangerous driving occasioning death.
Charlise's body was found in a sand-filled barrel on the banks of the Colo River four days after she was reported missing.
Stein claims he was in a shed on the property when he heard a gunshot, emerging to see the nine-year-old's mother Kallista Mutten shoot her daughter a second time.
The pair had allegedly stolen guns from a property months earlier.
Senior Constable Graeme Gray allegedly found those guns buried off a fire trail near the property in February, after Charlise had been found dead.
They were under a mound rising about 10 centimetres above the rest of the ground, covered in sticks, with a sliver of blue tarpaulin sticking out.
"This did not look like it belonged," Sen Const Gray told the court.
Wrapped in that blue tarpaulin, buried only centimetres under the ground, were the two guns and ammunition.
There was also a small piece of silver.
"I describe it as in the shape of a 'C'," Sen Const Gray told the NSW Supreme Court on Wednesday.
A rifle Sen Const Gray found was brought into the Parramatta courtroom as it became evidence in Stein's trial.
Justice Helen Wilson reassured the jury the gun was unloaded and could not do any damage before jurors passed it between themselves.
Pictures of the buried guns were previously shown to Stein's mother at Katoomba Police Station, the jury heard on Tuesday.
Stein, speaking to his mother on the phone from custody, told her he needed her to retrieve something he had dumped in the bush.
"I've got a feeling that they might already have them," Annemie Stein told her son.
Neither identified specifically what they were talking about in the recorded call.
The trial resumes on Thursday.
