The info on what he found has been released - at least enough of it to let them know there is plenty more that he's, to date, withheld. If he were to suddenly commit suicide (the PTB favorite way of getting rid of someone is to make it look like suicide as much as possible) then the rest of his info will come tumbling out.

Why else do you really think he is still alive? This bunch of thugs does NOT play nice! He's got much more on them and they know it. Keeping him alive may well be their only way to extract his silence!