Appear to expose a fraud (4,2)
I believe the answer is:
show up
This clue could be a double definition.
'appear' is the first definition.
(I know that show up is a more specific form of the action appear)
'expose a fraud' is the second definition.
'show up' can be an answer for 'expose' (thesaurus). I am not certain of the 'a fraud' bit.
'to' acts as a link.
Can you help me to learn more?
(Other definitions for show up that I've seen before include "Expose or keep appointment" , "Make an appearance" , "cause public embarrassment" , "Expose, or arrive as expected" , "Put in appearance or expose" .)