The homicide squad has ended a day of searching dense bushland for the body of three-year-old William Tyrrell who disappeared on the New South Wales mid-north coast five months ago.

Police discovered bones during their search today but tests confirmed they belonged to an animal.

William was last seen playing in his grandmother's backyard at Kendall, south of Port Macquarie, in September.

A large search failed to find any trace of the boy, who was wearing a Spider-Man suit when he disappeared, and it is now thought he did not wander off and get lost, but was taken.

Police operating on a tip-off spent the day scouring an area about 20 kilometres from where William was last seen, in search of his body and other evidence.

Officers are scheduled to return to the site to continue the operation at about 7:30am on Tuesday.

The search is being conducted in an area around Houston Mitchell Drive and Long Point Road in Bonny Hills over a number of days.

The area of dense bushland is just off the Pacific Highway, about 20 kilometres from Kendall.

The search is being coordinated by the homicide squad with assistance from the public order and riot squad, Operation Support Group, dog unit and water police.

About 30 police and more than 10 police cars, vans and police rescue trucks were at the site near Bonny Hills during Monday's operation.

The homicide squad said it was searching the area for the first time because of information from the public and its own enquiries.

A police source earlier told the ABC that officers were looking for the boy's body.

Detective Superintendent Michael Willing said police were not ruling out the chance that they may find a body.

"There is always that possibility but we are searching for evidence at this point," he said.

"The information is only general in nature."

Police have spoken to a number of people about William's disappearance, but no-one has been detained or charged.

Detective Superintendent Willing has confirmed the most likely scenario to explain the toddler's disappearance is that he was abducted.

"It's led us to believe that the most likely scenario is that he was taken by somebody," Detective Superintendent Willing said.

"There has been an intervention by a third party there."

Tradesman's home searched in January

In January, a team of homicide detectives, forensic police and officers searched the home and business of a tradesman at Bonny Hills.

The property's septic tank was drained and police also seized a number of items from the home.

Police have now confirmed the owner of the property, 63-year-old William Spedding, is a person of interest but have stressed it is not the only line of enquiry detectives are following.

The search is being coordinated by the Homicide Squad with assistance from the Public Order and Riot Squad. ( ABC News: Emma Siossian )

Officers also searched Mr Spedding's pawn shop at Laurieton and seized a number of items. Mr Spedding has reportedly cooperated with police.

Investigators are still appealing for more people to come forward with any information about William.

"Again, as is the case with these matters, somebody usually knows something," Detective Superintendent Willing said.

"We want that person or those people to come forward and provide us with the information that we need to find out what happened to William."

The Salvation Army Emergency Services set up a truck at the search site to offer refreshments to search crews.

Lachie McKay from the Salvation Army said the search for a body had affected many in the local community.

"Our job is to support everyone that needs support as far as meals and refreshments," Mr McKay said.

"Obviously no-one wants to be here for obvious reasons, but we are here to make it as comfortable for the people doing the search."