UPDATE: Police maintain hope for young boy’s survival as desperate search continues

Additional police crews have been sent to the NSW mid-north coast to expand the search for three-year-old William Tyrell, who was last seen wearing a Spider-Man suit in the front yard of his grandparent’s home on Friday morning.

Mounted police, dog teams, members of the SES, Rural Fire Service, the local surf lifesaving club and hundreds of volunteers will concentrate on a 1.5km radius around the home in Kendall, near Port Macquarie.

"We will continue to comb through very thoroughly that area close to where he was last seen," Police Superintendent Paul Fehon told a press conference this morning.

Police divers searched surrounding dams over the weekend for the boy, amid growing fears he may have been abducted.

Superintendent Fehon said police “don’t want to speculate at this stage” on the circumstances of his disappearance.

"We are keeping an open mind in regards to anything as part of our search operation and our investigation," he said.

"At this stage while there is hope for young William's survival, we'll search for him."

Superintendent Fehon said the Tyrell family was distraught and wanted to express their gratitude for support in the effort to find William.

William is described as being of Caucasian appearance, with dark hair and hazel eyes.