A human made it: a truth Irish broadcasters accepted (8)
I believe the answer is:
artefact
'a human made it' is the definition.
(man-made object)
'a truth irish broadcasters accepted' is the wordplay.
'truth' becomes 'fact' (fact can mean truth or reality).
'irish broadcasters' becomes 'RTE' (RT is Ireland's national broadcaster).
'accepted' is an insertion indicator.
'a'+'fact'='afact'
'afact' going around 'rte' is 'ARTEFACT'.
(Other definitions for artefact that I've seen before include "Item made by human" , "not natural" , "hand-made thing" , "Man-made object, of archaeological interest, perhaps" , "Something man made" .)