Four attorneys targeted for potential fraud in the dispersal of BP PLC’s $9.6 billion Deepwater Horizon oil spill settlement are fighting back, filing lawsuits, challenging court orders and alleging a conflict of interest.

Former FBI director Louis Freeh, appointed by U.S. District Judge Carl Barbier as special master to investigate potential corruption in the settlement’s claims process, in a September 6 report alleged improprieties in the claims process and referred four lawyers to federal authorities. Barbier has ordered the attorneys to respond by November 15.