Painter of a pole in the police? (5)
I believe the answer is:
manet
'painter' is the definition.
(I know this)
'a pole in the police?' is the wordplay.
'pole' becomes 'n' (abbreviation for North, as in North Pole).
'in' is an insertion indicator.
'the police?' becomes 'met' (London Metropolitan Police).
'a'+'n'='an'
'an' put inside 'met' is 'MANET'.
'of' acts as a link.
(Other definitions for manet that I've seen before include "Olympia artist" , "French painter" , "Edouard ---, pre-impressionist" , "Edouard -- (artist)" , "Painter of Le Dejeuner sur l'herbe, d. 1883" .)