This is the "second tranche" of the inquest into William's disappearance and suspected death, with previous hearings held briefly over a week in late March.
Senior Constable Kris Rattenbury gave evidence at the NSW Coroner's Court today about a four-week evidence search conducted by Strike Force Rosann in June 2018.
The first find of the search was a wooden cross pegged into the ground which the police officer believed marked a dog grave.
"It was identified that the markings of the grave were dated 2014," a statement from Sen-Constable Rattenbury, provided to the inquest, reads.
"The area was carefully dug up."
Mr Craddock asked: "But in order to determine that (it was such a grave), you had to dig down and discover the remains of a dog?"
"Yes," Sen-Constable Rattenbury replied from the witness box.
The second find was another cross, this time white, in a similar area "not too far from the cemetery" but it was not propped up.
The officer told Mr Craddock they did not excavate beneath it.
"It had been there for quite some time," he said.
"There was nothing that the detectives wanted to investigate.
"It wasn't in the ground, it was just lying on top, more like rubbish."
Coroner Harriet Grahame asked: "Does it sort of appear that near the cemetery, some people have taken the opportunity to take their pets there?"
"Possibly, yes," Sen-Constable Rattenbury said.
The officer also testified that a ramshackle cubby house, the sole of a child's shoe, chicken bones and rusted shovels were found during the search.
The comprehensive scope of the land involved dozens of people using "like a big, heavy duty rake" and each spaced two metres apart.
"The spacing allowed everyone to take a step forward, rake all the leaf litter and topsoil back, have a look in among that, take a step forward … and that's how the search line was going to run," Sen-Constable Rattenbury said.
He said they were looking for "human remains, anything of the like".
This included ground considered "abnormal" and treating any mound of dirt as suspicious until it was checked over by a cadaver dog.
"Anything a bit different to the area around it would be probed with a metal prod … (to) see if we could identify any sign of human remains," he said.
Photographs were taken of the chicken bones and sent away for further analysis.
"When that find was found, I waited with the detectives for quite a period of time while photos were sent back and forward to the (forensic) pathologists to determine what they were and it was later determined that it was chicken bones," Sen-Constable Rattenbury said.
He said the Police Search Advisors, or PolSAs, shared the finds with each other via a group discussion using the encrypted message application WhatsApp.
A handwritten log of their finds, maintained by another senior constable, has also been provided to the inquest.
The Strike Force Rosann search covered more than 40 hectares of bush immediately surrounding William's foster grandmother's home.
The court heard yesterday that toys, backpacks and a speargun were among further items uncovered but none were deemed to be related to the three-year-old's disappearance.
Senior Constable Grant Hollis confirmed to Mr Craddock that the first find — the small cross made of fence palings with handwriting on it — was above a dog's grave.
"It had a date on it, I believe, of 2014," he told the inquest.
"The significance there for me was that it was in the search area, it was probably 30 to 40 metres off a walking track and the date itself was the year that William Tyrrell had been missing.
"Therefore it struck my curiosity."
He said a police officer started to dig "not like you dig sand at the beach" but inch by inch and stopping in between.
The officer ultimately reached a bundle in blue plastic.
"The blue plastic was approximately about a foot long, about half a foot wide," Sen-Constable Hollis said.
"They unwrapped the plastic and discovered the corpse of a small dog."
He testified that find number five was considered a "shrine" of sorts by some within the search group.
"It looked like a doll's cubby house, some people described it as a shrine," he said.
"It was just made with homemade items like toilet rolls."
Sen-Constable Hollis said there was no problem in thinking a child had accessed the area and built a little cubby.
He agreed with Mr Craddock that it was fair to say there was "a lot" of rubbish in the forest.
More than 50 witnesses are expected to be called over the next month including a convicted paedophile and two mystery women with the pseudonyms "Amy" and "Tanya".
Mr Craddock has stressed any suggestion that those called to testify were suspects is "simply wrong".
Mr Craddock said he would not be calling any witnesses tomorrow as they are still waiting to get hold of some documents which are with a person who arrives back in Australia on Monday.
Ms Grahame said the inquest will resume on Monday with "different sorts of witnesses" unrelated to the forensic search.
