Firm punishment announced for Charlie (7)
I believe the answer is:
cocaine
'for charlie' is the definition.
(I've seen this before)
'firm punishment announced' is the wordplay.
'firm' becomes 'co' (a firm is a company).
'punishment' becomes 'cane' (I've seen this before).
'announced' indicates a 'sounds like' (homophone) clue.
'cane' sounds like 'caine'.
'co'+'caine'='COCAINE'
(Other definitions for cocaine that I've seen before include "Oceanic (anag) - drug" , "Addictive drug of oceanic origin" , "Charlie" , "Drug, crack" , "14 (anag)" .)