Officers would like to thank the media and the public for their help with this appeal.
When he was last seen by his mum William was wearing a black North Face hooded parka, grey tracksuit bottoms, black Nike 110 trainers.
He is known to ride a black mountain bike and has links to the Breckside Park and Richmond Park areas of Anfield.
Anyone who has seen William since Sunday or knows where he is now is urged to call Merseyside Police on 101 or Crosby police station on 0151 777 3674.
Submit News Contact us with your community, business or sport news. Phone 07581350321