Part of Middle East where fine accompanies crime (5)
I believe the answer is:
sinai
'part of middle east' is the definition.
(Sinai Peninsula)
'fine accompanies crime' is the wordplay.
'fine' becomes 'ai' (resembles A1, informal term for top quality).
'accompanies' means one lot of letters go next to another.
'crime' becomes 'sin'.
'ai' put after 'sin' is 'SINAI'.
'where' acts as a link.
(Other definitions for sinai that I've seen before include "Law handed down here" , "One showing genetic change" , "Mt. where Moses received 10 Commandments" , "Mountain in Egypt" , "Biblical mount" .)