Writer was aware of inside information (4,3)
I believe the answer is:
felt tip
'writer' is the definition.
(a felt tip pen is something which writes)
'was aware of inside information' is the wordplay.
'was aware of' becomes 'felt' (feel can mean to be aware of).
'inside information' becomes 'tip' (I've seen this in another clue).
'felt'+'tip'='FELT-TIP'
(Other definitions for felt tip that I've seen before include "Variety of pen" , "(Pen with) fibre point" , "writer" , "Type of pen" .)