There is some confusion 'concerning' [='regarding'] his current whereabouts.
news 'concerning' friends
(..) Not driving, anyway. - I was right about the bomb, wasn't I? - This is great. This is fitting. What? I have to be in Washington DC in hours for a hearing concerning my career. And I'm in the middle of nowhere, chasing phantom tanker trucks. We're chasing evidence. Of what? (..)1998 The X Files