Philosopher in wrongful arrest (6)
I believe the answer is:
sartre
'philosopher' is the definition.
(I've seen this before)
'wrongful arrest' is the wordplay.
'wrongful' is an anagram indicator (I've seen this in other clues).
'arrest' with letters rearranged gives 'SARTRE'.
'in' is the link.
(Other definitions for sartre that I've seen before include "Jean-Paul -, Fr. author" , "French existentialist philosopher and writer" , "Jean Paul . . ., French existentialist writer" , "Jean-Paul --, French writer and philosopher" , "Jean-Paul --, French author and philosopher" .)