William Tyrrell’s Spider-Man suit may be all we find: Expert

The bones of a child would likely break down in the soil that investigators have searched in Kendall but a polyester superhero costume wouldn’t, an expert said.

The Spider-Man costume William Tyrrell was last believed to be wearing could play a crucial part in finding out what ­happened to the toddler seven years on.

Geomorphologist Jon Olley said the bones of a child would likely break down in the soil that investigators have searched for more than three weeks in Kendall, near his foster grandmother’s home from where he vanished in 2014.

William Tyrrell wearing the Spider-Man suit he is believed to have disappeared in.

This additional picture of William in his Spider-Man suits was released at his inquest.

But the soil expert who is assisting NSW Police with the search said the polyester outfit would be still be intact to this day.

“The one thing we have going in our favour is the fact that (investigators) believe he was in a polyester suit. That doesn’t break down and it’s very resistant to actually fading as well,” Professor Olley said.

“There possibly would be bones, but given the level of bioactivity here, and the amount of humic acids that are in the soils, that would actually help break them down over time.

“Seven years for a child’s bones is a long time in this sort of environment. It is unlikely that a large proportion of the bones would be well preserved.”

Professor Olley has helped police across Australia with five missing persons and murder cases including the death of 13-year-old Daniel Moorcombe.

Detectives have received strong information placing William’s remains in the location they are searching, 30km south of Port Macquarie.

Mr Olley said investigators were certain William was not buried in the areas they have “thoroughly” searched with the help of cadaver dogs and an archaeologist.

He said if there was evidence the soil had been disturbed before by previous digging he could tell.

“The cadaver dogs come through, then we remove the shrubby vegetation, before the soil surface is chipped away. We then dig through the different layers of the soil,” he said.

“Everyone’s satisfied that where we have looked, he isn’t.”