He may be after news (in secret?) (5)
I believe the answer is:
agent
'he may be' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'news in secret?' is the wordplay.
'news' becomes 'gen'.
'in' indicates putting letters inside.
'secret?' becomes 'at' (I am not sure about this - if you are sure you should believe this answer much more).
'gen' inserted inside 'at' is 'AGENT'.
'after' is the link.
Can you help me to learn more?
(Other definitions for agent that I've seen before include "Bond, e.g." , "factor in Scotland" , "Vehicle" , "Catalyst" , "Spy - broker" .)