Inside information worried armed French policeman (8)
I believe the answer is:
gendarme
'french policeman' is the definition.
(French military police officer)
'inside information worried armed' is the wordplay.
'inside information' becomes 'gen'.
'worried' indicates an anagram.
'armed' is an anagram of 'darme'.
'gen'+'darme'='GENDARME'
(Other definitions for gendarme that I've seen before include "Member of the French police" , "French Connection cop" , "French officer - merge DNA (anag)" , "French copper" , "continental copper" .)