The day has seen a series of major developments in the search for missing child William Tyrrell.

Police have confirmed the sole person of interest in the case is William’s foster mother, who has always strenuously denied any involvement in his disappearance.

His foster grandmother’s car has been seized and will undergo extensive forensic examinations.

Both foster parents have been charged in relation to the common assault of a child. That child is not William and he has no connection to those charges.

University of Newcastle forensic anthropologist and criminologist Dr Xanthe Mallet told Jim Wilson detectives have provided a great deal of detail about the renewed search effort because they are still seeking public assistance.

“They reminded us that that million dollar reward is available for information leading to discovery of the whereabouts of William.

“It’s also a very high profile case.

“I am quite surprised at how much information is coming out, it is quite unusual to be getting as much as we are, but obviously strategically the police think this is the right way to engage.”

Dr Mallet said the details released by police shouldn’t endanger any future convictions, but warned social media discussion could prejudice a trial.

“Just like with the Cleo Smith case, I’d caution people against hypothesising.”

Press PLAY below to hear Dr Mallet’s analysis of the day’s developments

Image: NSW Police