Maintained a member took part in a crooked deal (7)
I believe the answer is:
alleged
'maintained' is the definition.
(alleging is a kind of maintaining)
'a member took part in a crooked deal' is the wordplay.
'a member' becomes 'leg' (member can mean a limb).
'took part in' indicates putting letters inside.
'a crooked' indicates an anagram (a crooked or disrupted version of the letters).
'deal' is an anagram of 'aled'.
'leg' placed into 'aled' is 'ALLEGED'.
(Other definitions for alleged that I've seen before include "Asserted but not proven" , "Declared without proof" , "Accused, though without proof" , "Claimed (without proof)" , "Stated without proof" .)