Renounce, as police personnel have (6)
I believe the answer is:
'renounce' is the definition.
(I know that renounce can be written as disown)
'police personnel have' is the wordplay.
'police personnel' becomes 'DIs' (detective inspectors).
'have' becomes 'own' (to have something is to own it).
'as' acts as a link.
(Other definitions for disown that I've seen before include "Disclaim or deny" , "Reject all connection with, refuse to acknowledge" , "Repudiate, cast off" , "Cast aside" , "Refuse to be associated with (a person)" .)