A four-day fresh police search is underway on the NSW mid-north coast as part of ongoing investigations into the disappearance of young William Tyrrell.

The search, now in its second day, saw specialist riot squad police, sniffer dogs and SES crews arrive to search in the vicinity of Herons Creek, just 10 minutes’ drive away from the town of Kendall.

Three-year-old William vanished from his foster grandmother’s home on Benaroon Drive in 2014.

Channel 7 News reported Counsel assisting the coroner, Gerard Craddock SC arrived on the scene on Tuesday morning as crews entered bushland with whipper snippers and chainsaws.

Under a coronial order, police are understood to be conducting further searches, cutting through thick bush around Walkers Creek next to an old train line, amid the ongoing inquest.

The ABC reported investigators are focusing on an area near an old saw mill, where convicted pedophile Frank Abbott lived in a caravan at the time of William’s disappearance on the morning of September 12, six years ago.

Police were expected to return to the area on Tuesday.

The coronial inquest into the boy’s suspected murder previously heard the 79-year-old Abbott would often ramble to neighbours about the smell of a “dead human” near Herons Creek.

He became obsessed with the high profile case and remains a person of interest, the ABC reported.

Police and support agencies have previously focused on the area, with extensive searches conducted in February, in August last year and a four-week search of a 40-hectare tract of forest in 2018.

Abbott, who is in a Cessnock jail on an unrelated conviction, was questioned by police in late 2019.

An inquest into William’s disappearance is expected to resume in October after COVID-19 prompted its adjournment in March.

Counsel assisting the coroner, Gerard Craddock SC, told a hearing earlier this month that there were people with information about the boy’s disappearance and suspected death who should contact police.

No one has been charged in relation to William’s disappearance.

Hundreds of people have been dubbed “persons of interest” during the investigation and a case detective admitted during the inquest there’s “a very low standard to meet in order to become a person of interest”.

Counsel assisting the coroner Gerard Craddock SC in August stressed that any suggestion those called to give evidence were suspects was “simply wrong”.

-with AAP