Investigators are focusing the search on an area where convicted paedophile Frank Abbott lived in a caravan at the time of William's disappearance, according to the ABC.
Abbott is currently serving 16 years in jail after being convicted of 10 counts of sexual misconduct against three children.
A coronial inquest into the toddler's disappearance previously heard how the 79-year-old would complain about a "peculiar smell" coming from the bushland near Herons Creek.
When someone known to Abbott suggested it was probably a dead kangaroo, he reportedly said, "I know the difference between a dead kangaroo and a dead human".
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He reportedly didn't tell the police about the smell because he believed he would get blamed "if there's something up there".
Police also conducted another search of bushland near Kendall in February this year.
The search was understood to be in relation to an order made by Deputy State Coroner Harriet Grahame who is overseeing the ongoing inquest.
