Breaks FBI agents implicated by fellow informers (9)
I believe the answer is:
fragments
'breaks' is the definition.
(fragmenting is a kind of breaking)
'fbi agents implicated by fellow informers' is the wordplay.
'fbi agents' becomes 'g-men' ('G-man' can be a synonym of 'fbi agent').
'implicated' indicates putting letters inside (I've seen this in other clues).
'by fellow' becomes 'f' (abbreviation - of a society etc.. I am not sure about the 'by' bit.).
'informers' becomes 'rats' ('rat' can be a synonym of 'informer').
'f'+'rats'='frats'
'gmen' going inside 'frats' is 'FRAGMENTS'.
Can you help me to learn more?
(Another definition for fragments that I've seen is " 'Small pieces, perhaps broken (9)'".)