Briley was last seen on 4 April in the Frankston area.
Police have concerns for his welfare due to his age and the length of time he has been missing.
Briley is 170cm tall with a thin build, fair complexion and dark brown hair.
Briley is known to frequent the Hastings and Clarinda areas.
Police have also released an image of Briley in the hope someone recognises him and can provide information regarding his current whereabouts.
Anyone with information about Briley is asked to contact Mornington Police Station on 5970 4900.
