Deception is barely detectable in report (5)
I believe the answer is:
feint
'deception' is the definition.
(thesaurus)
'barely detectable in report' is the wordplay.
I cannot really see how this works, but
'in' is found in the answer.
The remaining letters 'fet' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'is' is the link.
Can you help me to learn more?
(Other definitions for feint that I've seen before include "ruled lightly" , "Sell a dummy" , "Mock attack" , "Pretended blow" , "(Make a) deceptive move" .)