The son of tradesman Bill Spedding says his father had nothing to do with the disappearance of three-year-old William Tyrrell as police scour bushland for evidence, including the toddler's red and blue Spider-Man suit.

Rodney Spedding said his father had been unfairly harassed by the media, even though a number of other homes and properties had been searched by police – some up to three times, he believed.

"He's got the biggest heart, he's very generous. Bill has our full support, and [has] no link to the disappearance," Mr Spedding told Fairfax Media on Tuesday afternoon.

"I feel very upset, it's upsetting. The media attention has killed his business, and it's affected his livelihood."

Police divers are expected to search a murky creek in bushland between Bonny Hills and Lake Cathie on Wednesday morning.

A search involving 30 officers began on Monday but a police source has told Fairfax Media that only a few soft drink cans and a number of logging markers had been found so far.

The source also said police were on the look out for William's favourite Spider-Man suit and any other items of interest.

Mr Spedding's Bonny Hills home and Laurieton office was raided by police in January, following William's disappearance from his grandmother's home in September.

The 63-year-old became a focus of investigations after police learned he was due to fix a washing machine at William's grandmother's house about the time the toddler disappeared.

Searchers have not been directly told to look for a body but the homicide detective in charge of the investigation said it was always a possibility.

"Of course when we are looking for evidence that would also include a body," Detective Inspector Gary Jubelin said at the search site.

"Clearly the fact and the resources that we dedicated to the search we thought it was worthwhile information to follow up," he said.

Police have repeatedly said Mr Spedding was not a suspect but a person of interest but he has been the subject of intense media scrutiny in the past several weeks.

Mr Speeding's son said he wished police would publicly rule his father out of the investigation but understood they had a job to do.

"He doesn't need the attention he is getting it just seems media have singled him out for some bizarre reason."

"I was hoping by now they [the police] would come out and say there is no link."

He said most of the community on the mid-north coast had been very supportive of his father but that it had taken a hard toll.

"It's been terrible. When it all started [the first police search of his home], they took his phone off him and we weren't able to contact him and find out what was going on," he said.

"It was very, very hard and it's been very hard on Bill and Margaret."

Mr Spedding said he and one of his sisters would continue to support their father and hoped police would soon find William.

"I'd like to see him found alive and well. I'd love to see them find him - it would be really, really good."

The current search of bushland is six kilometres from Mr Spedding's Bonny Hills home and 21 kilometres from the town of Kendall where William was last seen.

Detetective Inspector Jubelin has said the search was initiated after "fresh information" was received in recent weeks and was expected to wrap up on Wednesday afternoon.

"There will be further searches, when and where that will be I'm not prepared to say."

Anyone with information was urged to call Crime Stoppers on 1800 333 000