A detective involved in the William Tyrrell investigation has told a court he has formed the belief his foster mother knows where the missing boy is.
The 57-year-old woman, who cannot be identified for legal reasons, today appeared in Sydney's Downing Centre Local Court over allegations she gave misleading or false evidence to the NSW Crime Commission, which she denies.
Last year, both foster parents were charged with the alleged common assault of a child at a home on Sydney's north shore. The child is not William.
During evidence today from Detective Sergeant Andrew Lonergan, it was revealed today police obtained warrants to plant multiple listening devices in two locations and had also intercepted the parents' phone calls.
Under cross-examination, he agreed he was aware the foster mother had complained about a lack of progress in the William Tyrrell investigation, following his disappearance in 2014.
Defence barrister John Stratton SC put to the detective that one of the reasons for laying charges was to "break [the foster mother's] spirit".
He said she was given an opportunity, in the Crime Commission, where she could "tell the truth and she wouldn't be punished for it".
Mr Stratton suggested the detective had formed "a false belief" that the defendant knows where the body of William Tyrrell is.
"I've formed the view that [the defendant] knows where William Tyrrell is," the witness replied.
Detective Lonergan agreed the only matter over which the woman has been charged for giving false evidence to the Crime Commission were answers she gave about the alleged assault.
"Yes, that's true, or else I would have charged her with more offences," he said.
At that point, the foster mother turned to a supporter in court, with her mouth open.
In June, it was revealed in a Parramatta court that the assault charge related to an allegation a girl was hit in the head with a wooden spoon and kicked in the thigh.
Today, the Downing Centre court was played two audio files; one from a listening device in a home and a second from an intercepted phone call between the foster parents.
In the first clip of audio, a voice can be heard repeatedly yelling "no", before a female voice says: "Stand up. Stand up. Where did you put the wooden spoon".
During the phone call, the foster mother is heard saying: "She locked me out of the house."
A male voice then replies: "That's not good … we've got a problem, we've got a big problem."
The hearing continues.
