People in authority have taken back prize money (3,5)
I believe the answer is:
top brass
'people in authority' is the definition.
(I've seen this before)
'taken back prize money' is the wordplay.
'taken back prize' becomes 'top' (I am not sure about this - if you are sure you should believe this answer much more).
'money' becomes 'brass' (I've seen this before).
'top'+'brass'='TOP-BRASS'
'have' is the link.
Can you help me to learn more?
(Other definitions for top brass that I've seen before include "Most important leaders, officers, etc" , "High-ranking figures of authority" , "management" , "senior command" , "Senior military personnel" .)