For residents of Kendall, this is one of a number of instances over the past seven years since the then three-year-old disappeared, that police have descended on the village to search for answers.

Day leader of the Kendall Community Op Shop Janet Lewin said each time investigators return to the small country town, the memories of what happened on September 12, 2014 resurface.

"Every time (there is a new search) Kendall goes through it again and again," she said.

"There are a lot of us in town that were here seven years ago and remember what it was like when he first went missing and each time a new search happens, everyone swoops in here from Sydney and then leaves."

Mrs Lewin is also concerned about opinions on the case being posted by the public on Facebook groups.

"I'm horrified by it and I know there are other people who are outraged by it as well," she said.

Strike Force Rosann has spent the past four days combing through two specific search areas - one at the Benaroon Drive home formerly owned by William Tyrrell's late foster grandmother and another at the corner of Cobb and Co Rd/Batar Creek Rd one kilometre away - to find any evidence of the missing boy.

"Everyone is talking about it. People who come into the shop are mentioning it and we also talked about it in my quilting group last night," Mrs Lewin said.

"We've all been through it before, it's very sad. We do hope that it's over and hopefully there will be answers."

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The Australian Federal Police today (November 18) used specialist subterranean equipment at the home on Benaroon Drive to detect any disturbances or abnormalities in the ground under a concrete slab in the garage.

The current home owner is working with the investigation team to ensure they have full access to the property.

A NSW Police spokesperson said if there are any disturbances detected underneath the garage, further testing will be required before a decision is made to excavate the area.

An item found at the Cobb and Co Rd/Batar Creek Rd search location on Wednesday (November 17) afternoon has been sent away for forensic analysis to the Forensic and Analytical Science Service (FASS) in Sydney.

A NSW Police spokesperson said it could be a number of days before the results from the forensic examination are determined.

A tarp that had been placed over the site where the item was found on Wednesday has been removed, with police sifting through soil and sweeping through the search area. However, there will be no further digging at that location until the item is analysed, a NSW Police spokesperson said.

Rural Fire Service volunteers (RFS) are supporting the investigation team by moving further into the Cobb and Co Rd/Batar Creek Rd location and assisting with the removal of trees.

Meanwhile, Prime Minister Scott Morrison has praised police officers investigating the disappearance of William Tyrrell, saying they've made "huge inroads", as the search for the boy's remains continues.

Mr Morrison said police would "never stop" looking into the case after the three-year-old vanished seven years ago, and that it was a great statement about the dedication of police, AAP reported.

"My late father was a policeman so I have a bit of an inkling about the level of patience and determination required from law enforcement to never give up," Mr Morrison said.

He thanked police for their "extraordinary work", which he said had led to "huge inroads" which he hoped would give William's family some comfort.

NSW Premier Dominic Perrottet has described the William Tyrrell case as a 'tragedy' in commending Strike Force Rosann's renewed and rigorous efforts to bring closure to a mystery that has brought investigators back to where it all started.

The latest search, according to NSW Police Commissioner Mick Fuller, has zeroed in on 'one particular person'.

He was also publicly critical of earlier investigative work in the case as being "a bit of a mess". The team now under Chief Inspector David Laidlaw, he said, is the "best we've got".

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