The foster family of missing Sydney boy William Tyrrell has vowed to never give up searching for their "precious little boy", on the eve of the third anniversary of his disappearance.
The three-year-old was last seen on September 12, 2014, in the front garden of a home in Kendall, south of Port Macquarie, with NSW police a year ago offering a $1 million reward for information leading to his return.
William's family took to Facebook on Monday to say how the past three years have involved "unspeakable heartbreak and endless tears".
"William, we will never stop loving you," the statement said.
"We will never stop looking for you, and until the tomorrow we yearn for comes, we will never give up hope that you will be found and returned home to the arms of your loved ones where you belong."
William's foster-care status was only revealed publicly last month after the Department of Family and Community Services failed in a bid to prevent an advocacy group from publishing the fact in calls for a coronial inquiry.
The NSW Court of Appeal upheld a January decision from the NSW Supreme Court which cited significant public interest and the need for scrutiny of the state's foster care system.
The case weighed up the competing interests of William's foster family, which wishes to remain anonymous, his older sister and the homicide detectives who've been relentlessly pursuing leads for three years.
It also delivered a disheartening recognition from the judiciary that the likelihood of finding William alive has decreased with the passage of time.
A long-running campaign to find the missing boy, who would now be six, will roll out this week in a digital ad campaign advertising the $1 million reward on billboards and in shopping centres and businesses across the nation.
© AAP 2017
A supplied image obtained Saturday 13th Sept, 2014 shows three year old boy William Tyrrell, missing from a home in Kendall NSW. (AAP IMAGE/NSW POLICE)