Rich patron from Benin found by police in south of France (5,5)
I believe the answer is:
sugar daddy
'rich patron' is the definition.
'benin found by police in south of france' is the wordplay.
'benin' becomes 'dy' (vehicle code - Benin was formerly Dahomey).
'found by' says to put letters next to each other.
'police' becomes 'garda' (I have seen 'Irish police' mean 'garda' so perhaps 'police' could also mean 'garda'**).
'in' indicates putting letters inside.
'south of france' becomes 'sud' (French for south).
'garda' inserted inside 'sud' is 'sugardad'.
'dy' put after 'sugardad' is 'SUGAR-DADDY'.
'from' is the link.
(Other definitions for sugar daddy that I've seen before include "Older man lavishing gifts on girl" , "(Sweet) older lover?" , "Older, richer male partner" , "Rich man with a much younger partner" , "Rich man with a much younger girlfriend" .)