He said while police could not rule out that the bones belonged to William, it was unlikely.
"There speculation about William Tyrell being our victim, I can tell you that unnecessary speculation is not necessarily helpful to us and we have no evidence at all to prove that William Tyrell is the victim," he said.
"And in fact there are a number of things and information within our possession, which make it unlikely.
"We can't say that it's definitely not William Tyrell, but we say that we believe, at this stage [and] knowing the full facts of the case, that it's less likely."
http://www.abc.net.au/news/2015-07-17/child-bones-in-sa-unlikely-those-of-william-tyrell/6628908