Search for William Tyrrell continues on his 7th birthday

Police are describing it as “another milestone without answers” – today would have been William Tyrrell’s 7th birthday.

William disappeared from his grandparent's house in Kendall, on the NSW mid-north coast on September 21, 2014, aged three.

Almost four years later, police - led by Strike Force Rosann – were continuing to comb bushland near the property, two weeks after investigators launched a fresh search for evidence for the boy who seemingly disappeared without a trace.

“While we are obviously thinking of William and his loved ones every day, today is particularly tough as we know it’s another milestone without answers,” Detective Chief Inspector Gary Jubelin said on Tuesday.

“As such, our focus remains on providing his family with answers, and our investigation, along with the search of bushland at Kendall, is continuing today.

“I want to thank the community for their ongoing support, particularly the local community, who have been very understanding and accommodating during the forensic search.”

Earlier this month a forensic search was launched, sparking speculation that police are laying groundwork for an inquest.

Expected to last for four weeks, the operation aims to leave "no stone unturned".

Det Insp Jubelin said this operation would be small but "more intense" than the previous search, concentrating on about three square kilometres.

He said authorities held "grave fears" over finding William alive nearly four years after he vanished.

"It has been a very long time," he said.

"The purpose of this is that so if we present evidence to a court, we can show beyond reasonable doubt that William's disappearance was a result of human intervention and not through misadventure."

William's foster parents and biological parents have all been ruled out as suspects in the disappearance.