Controversial detention shocked Australians (11)
I believe the answer is:
tendentious
'controversial' is the definition.
Both the definition and answer are adjectives. Perhaps you can see a link between them that I don't see?
'detention shocked australians' is the wordplay.
'shocked' indicates an anagram (letters are shocked or disrupted).
'australians' becomes 'us' (I can't explain this - if you can you should give a lot more credence to this answer).
'detention' is an anagram of 'tendentio'.
'tendentio'+'us'='TENDENTIOUS'
Can you help me to learn more?
(Other definitions for tendentious that I've seen before include "Having deliberate bias towards a controversial view" , "Designed to promote a particular point of view" , "partisan" , "Purposely biased (towards controversy)" , "Purposeful" .)