Any body know his Sir name ? if not ask his previous employer , Oceansun
Look up his home tell number if there is one via T ..... or C........
If its unlisted - someone who you know working @ telkom should be able to look it up.
Call the police and check for missing person's report.
Or May by there was some kind of legal misunderstanding and hes been detained by the police as luckyfish was, but the family is a bit embarrassed to say anything.
If you have a contact in the police , you could ask them to do some digging arround with Trevs Sirname and the approxamate date of absence.
I will obviosly be quite embarressed if its nothing like that and its not nice to plant seeds, but its just a sugestion to narrow down the possibilaties for every one involved.