Criminal group missing in action having abducted American fellow (5)
I believe the answer is:
mafia
'criminal group' is the definition.
(I've seen this before)
'missing in action having abducted american fellow' is the wordplay.
I cannot really see how this works, but
'american' could be 'a' (common abbreviation - e.g. in organisation names) and 'a' is found in the answer.
'fellow' could be 'f' (abbreviation - of a society etc.) and 'f' is located in the answer.
The remaining letters 'mia' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for mafia that I've seen before include "The Sicily mob" , "connection claimed to 23 [JFK]" , "Our family" , "organised criminals" , "Sicilian criminal body" .)