Johannesburg - Forensic investigator Paul O'Sullivan and Agang SA decided to go their separate ways, the party said on Friday.
Agang spokesperson March Peach thanked O'Sullivan for his contribution to the party.
Agang named O'Sullivan on its parliamentary list in March.
"Paul O'Sullivan and Agang have mutually agreed that he will continue to devote his full attention to fighting against corruption as a private forensic investigator and will therefore no longer be active in the political structures of the party," Peach said.
By late Friday afternoon, Mamphela Ramphele's party had received 50 378 votes, or 0.28% of the vote, in preliminary national election results.
The party looked to be on track to get one seat in the National Assembly.