National emblem featuring in disclosure, reportedly (4)
I believe the answer is:
leek
'national emblem' is the definition.
(I've seen this before)
'disclosure reportedly' is the wordplay.
'disclosure' becomes 'leak' (leak is a kind of disclosure).
'reportedly' shows a homophone (sound like).
'leak' is a homophone of 'LEEK'.
'featuring in' acts as a link.
(Other definitions for leek that I've seen before include "English town" , "Staffordshire town?" , "Vegetable symbol of Wales" , "Vegetable related to onions" , "Eat the vegetable and keel over" .)