Frank Abbott has been involved with a fiery exchange at the William Tyrrell inquest in which a witness said the convicted sex offender knows "something".
Anna Baker was recalled on Wednesday to allow Abbott to ask further questions about her prior evidence of hearing a boy's scream emanate from bushland behind her Herons Creek property on the NSW mid-north coast.
Occurring about 3.30pm the day after William went missing in September 2014, Ms Baker reported it to police in 2018 after learning Abbott had lived in the vicinity at that time.
Abbott, who was later convicted of child sex offences and is currently in a Cessnock jail, suggested Ms Baker didn't hear the noise from his place "because the distance was too great".
She said the noise came from bush to the left of her backyard, while Abbott's home was in bush to the right.
"You're the only person who lives there and you're a pedophile," she said.
"So it makes sense.
"You know something, Frank Abbott."
The pair spoke over each other often as coroner Harriet Grahame tried to restore order, eventually asking Ms Baker to take a breath.
William was aged three and dressed in a Spider-Man suit when he went missing from his foster grandmother's home in Kendall on September 2014.
The inquest, in its fourth and final round of hearings, has previously heard Abbott was "obsessed" with the search for William.
In 2014, Abbott lived in a caravan on a property on Herons Creek Road - about four kilometres from Kendall.
"When I found out you lived there, I couldn't sleep," Ms Baker said to Abbott on Wednesday.
Abbott suggested the scream may have been been a girl - something Ms Baker doubted but said was possible.
"I have formed an opinion you only (reported it) because of the offences I'm on and the reward money," the prisoner said.
"Oh, don't be stupid," Ms Baker replied, "I want to find William."
Abbott said he was in the same boat: "I want to find William too."
"I'm not in your boat, mate. Don't do that to me," Ms Baker replied.
Ms Baker on Tuesday said she'd been tending her strawberry patch the day after William went missing when she heard a boy scream.
"It was a scream and it was silence pretty quickly ... I had no reason to think it was William."
Abbott is not on the witness list and is not expected to give evidence to the inquest.
No trace of William has ever been found and no person has ever been charged.
The current supervisor of the police investigation, Detective Chief Inspector David Laidlaw, on Wednesday said he and four other investigators continue to work the case with two intelligence analysts.
"We never will (give up)," he said.