Federal authorities are scrutinizing private consultants hired to clean up financial misdeeds like money laundering and foreclosure abuses, taking aim at an industry that is paid billions of dollars by the same banks it is expected to police. The consultants operate with scant supervision and produce mixed results, according to government documents and interviews with prosecutors and regulators. In one case, the consulting firms enabled the wrongdoing. The deficiencies, officials say, can leave consumers vulnerable and allow tainted money to flow through the financial system. The pitfalls were exposed last month when federal regulators halted a broad effort to help millions of homeowners in foreclosure. The regulators reached an $8.5 billion settlement with banks, scuttling a flawed foreclosure review run by eight consulting firms. In the end, borrowers hurt by shoddy practices are likely to receive less money than they deserve, regulators said. Critics concede that regulators have little choice but to hire outsiders for certain responsibilities after they find problems at the banks. The government does not have the resources to ensure that banks follow the rules. Some banks that work with consultants continue to run afoul of the law. At other times, consultants underestimate the extent of the misdeeds or facilitate them, preventing regulators from holding institutions accountable.