WA Police and the Department of Communities are seeking assistance from the public to locate 10-year old Declan Hall-Alger.
Declan went missing with 14-year-old Tyrell Hall-Alger in Boxing Day, sparking concerns for their wellbeing among WA Police and the Department of Communities staff.
Tyrell was found on Tuesday but authorities continue to search for Declan, who was last sighted in Lockridge on Boxing Day.
Declan is about 130cm tall, with blonde hair and light skin and is of slight build.
Anyone who sees Declan, has information on his whereabouts or is able to assist in locating him, should contact police immediately on 131 444, or call Crime Stoppers on 1800 333 000.