Noblewoman’s fiddle, item of value must be returned (8)
I believe the answer is:
contessa
'noblewoman's' is the definition.
(female version of a count in some countries)
'fiddle item of value must be returned' is the wordplay.
'fiddle' becomes 'con' (both can mean a scam).
'item of value' becomes 'asset' (an asset is something valuable or advantageous).
'must be returned' shows that the letters should be reversed in order (letters sent back).
'asset' backwards is 'tessa'.
'con'+'tessa'='CONTESSA'
(Other definitions for contessa that I've seen before include "Italian noblewoman" , "European noblewoman" , "High-ranking female" , "Italian lady" , "noble foreign lady" .)