Bombshell revelation about William Tyrrell investigation as lead cop makes claim about foster mum

William Tyrrell disappeared from his foster grandmother’s house in 2014. Photo / NSW Police

A senior detective in the William Tyrrell investigation has sensationally revealed in court he believes the missing boy’s foster mother knows where the 3-year-old’s body is buried.

The bombshell claim was made in Sydney’s Downing Centre Local Court this afternoon as the foster mother - who cannot be named - has pleaded not guilty to giving false or misleading evidence to the NSW Crime Commission.

Police allege the foster mother lied or misled NSW Crime Commission officials when she told a secret hearing that she did not strike a child with a wooden spoon.

The court was played audio from a listening device planted in her home by police and it’s alleged that audio picks up her striking a child - not William Tyrrell - with a spoon.

It’s further alleged that a phone tap picked up the foster mother talking with her partner about the wooden spoon incident.

Under cross-examination from defence barrister John Stratton, a senior detective on the investigation told the court that he believed that the foster mother was aware of where William was buried.

William Tyrrell’s body has never been found. Photo / NSW Police Media

“I’ve formed the view that [the foster mother] knows where William Tyrrell is,” Detective Sergeant Andrew Lonergan told the court.

However, he denied she was charged with lying to the Crime Commission in an effort to put pressure on her as part of the homicide investigation.

“It’s not the purpose but if it’s of assistance...” Lonergan said.

During a fiery opening to the hearing, Lonergan was accused by Stratton of lying about his motivations for charging the woman.

William was in the care of the woman and her partner when he vanished in 2014 while at his foster grandmother’s home on the NSW Mid-North Coast.

No one has ever been charged over his disappearance and the foster parents deny any knowledge or involvement.

The foster mother is facing a two-day hearing before magistrate Miranda Moody.

William’s foster father, who cannot be named, also pleaded not guilty this year to two charges of giving false or misleading evidence to the commission.