Official stealing note from bank (3)
I believe the answer is:
ref
'official' is the definition.
(match official in football, say)
'stealing note from bank' is the wordplay.
'stealing' means one lot of letters goes inside another.
'note' becomes 'e' (musical note).
'from bank' becomes 'rf' (I can't justify this - if you can you should give a lot more credence to this answer).
'e' going within 'rf' is 'REF'.
Can you help me to learn more?
(Other definitions for ref that I've seen before include "Football's whistler" , "In brief, he controls a soccer match" , "One traditionally in black" , "Whistleblower (abbr)" , "Sports official (abbrev.)" .)