Reportedly noticed part of the play (5)
I believe the answer is:
scene
'part of the play' is the definition.
('scene' is part of 'play')
'reportedly noticed' is the wordplay.
'reportedly' indicates a 'sounds like' (homophone) clue.
'noticed' becomes 'seen' (I've seen this before).
'seen' sounds like 'SCENE'.
(Other definitions for scene that I've seen before include "Part of a pantomime" , "View, landscape" , "Setting - carry-on" , "bit of an act" , "Division of a play" .)