Heartless official in a tight spot (6)
I believe the answer is:
corner
'a tight spot' is the definition.
'corner' can be an answer for 'spot' (corner is a kind of spot). I am not certain of the 'a tight' bit.
'heartless official' is the wordplay.
'heartless' means to remove the middle letters.
'official' becomes 'coroner' (I've seen this before).
'coroner' with its centre removed is 'CORNER'.
'in' is the link.
Can you help me to learn more?
(Other definitions for corner that I've seen before include "set-piece" , "pickle" , "Difficult position; angle" , "Gaming establishment" , "Football kick; trap" .)