Remove arresting officer? That’s quite revealing (9)
I believe the answer is:
decollete
'quite revealing' is the definition.
(decollete means having a low neckline)
'remove arresting officer?' is the wordplay.
'remove' becomes 'delete' (deleting is a kind of removing).
'arresting' indicates putting letters inside.
'officer?' becomes 'col' (short for colonel).
'delete' placed around 'col' is 'DECOLLETE'.
'that's' acts as a link.
(Other definitions for decollete that I've seen before include "baring chest" , "Of clothes, low-cut" , "Having a low neckline, from French" , "low-cut dress!" , "Low cut" .)