Reportedly run away from bloodsucker (4)
I believe the answer is:
flea
'bloodsucker' is the definition.
(I've seen this before)
'reportedly run away' is the wordplay.
'reportedly' indicates a 'sounds like' (homophone) clue.
'run away' becomes 'flee' (I've seen this before).
'flee' sounds like 'FLEA'.
'from' is the link.
(Other definitions for flea that I've seen before include "Bug" , "Tiny circus performer?" , "Little jumping insect" , "Small parasitic insect" , "Biting type" .)