City where leaders' money is now secretly kept (5)
I believe the answer is:
minsk
'city' is the definition.
(capital of Belarus)
'leaders' money is now secretly kept' is the wordplay.
'leaders'' indicates taking the first letters (I've seen 'leader of' mean this).
The initial letters of 'money is now secretly kept' is 'MINSK'.
'where' acts as a link.
(Other definitions for minsk that I've seen before include "E European capital" , "Capital of Belarus" , "Capital of 15" , "Russian city" , "capital city" .)