Help whistleblower to suppress story (6)
I believe the answer is:
relief
'help' is the definition.
(relief is a kind of help)
'whistleblower to suppress story' is the wordplay.
'whistleblower' becomes 'ref' (referee).
'to suppress' is an insertion indicator.
'story' becomes 'lie' (I've seen this before).
'ref' placed around 'lie' is 'RELIEF'.
(Other definitions for relief that I've seen before include "That's a load off my mind" , "Comfort; easing" , "Alleviation or support" , "Alleviation - charity - raised decoration" , "Person replacing another on duty" .)