Help whistleblower to suppress story (6)
I believe the answer is:
Here is my best explanation:
'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 "Cosmos", "welfare", "Help or easement", "Support", "Freeing of besieged city", "Alleviation, easing", "Comfort; easing", "Rest - cure", "Easement or assistance to people in need" and "That's a load off my mind".)