Current Attorney General Michael Mukasey and some aides fear the department appears to be in a conflict of interest, because one of Ashcroft's former underlings, New Jersey prosecutor Christopher Christie, appointed Ashcroft Group to supervise Zimmer following a criminal investigation into alleged kickbacks to doctors.
Mukasey has made a point of ridding the department of political influences after his predecessor and Ashcroft's successor, Alberto Gonzales, became entangled in a string of scandals.
The internal review was reported in today's New York Times.
The Justice Department issued a statement saying the review was not prompted by the Ashcroft contract.
The Department settled the kickback charges out of court last fall.
Christie, a U.S. attorney, suggested to Zimmer that it hire Ashcroft Group to monitor its practices. The 18-month contract is valued at $28 million to $52 million.
Christie has steered additional monitoring contracts to other former Justice coworkers.
Under President Bush, such agreements with federal prosecutors mushroomed to 35 in 2007 from five in 2003. The out-of-court settlements spare companies indictments and trials.