Help whistle-blower to pen story (6)
I believe the answer is:
relief
'help' is the definition.
(relief is a kind of help)
'whistle-blower to pen story' is the wordplay.
'whistle blower' becomes 'ref' (I've seen this in other clues).
'to pen' means one lot of letters goes inside another.
'story' becomes 'lie' (I've seen this before).
'ref' enclosing 'lie' is 'RELIEF'.
(Other definitions for relief that I've seen before include "Easing of pain" , "new person on duty" , "Substitute" , "Ease given by removal of anxiety" , "Easement or assistance to people in need" .)