Severely criticise case of auditors mired in corruption (5)
I believe the answer is:
roast
'severely criticise' is the definition.
(I've seen this before)
'case of auditors mired in corruption' is the wordplay.
'case of' suggests removing the centre (outsides of).
'mired in' is an insertion indicator (some letters get trapped or mired in others).
'corruption' becomes 'rot' (rot can mean corruption or decay).
'auditors' with its centre taken out is 'as'.
'as' placed inside 'rot' is 'ROAST'.
(Other definitions for roast that I've seen before include "Become very warm" , "Cooked meat; criticise" , "Feel hot" , "Cooked like chestnuts tonight" , "Slate" .)