Dismembered body in a trunk (5)
I believe the answer is:
torso
I believe this clue is a double definition.
'dismembered body' is the first definition.
(central part of body excluding limbs and head)
'trunk' is the second definition.
(both can mean a person's chest)
'in a' is the link.
(Other definitions for torso that I've seen before include "Main part of human body" , "Body, minus its head and limbs" , "Body without head, neck and limbs" , "Roost on trunk?" , "unfinished work" .)