"If the Afghan government continues not to take action against public officials who violate internal codes of ethics, while simultaneously failing to protect reformers and whistle-blowers from reprisal, a climate of corruption will endure," the report said on Wednesday.
Afghan police are reluctant to arrest people whose bodyguards are better armed than they are, and are discouraged by politically powerful individuals into not opening some cases, SIGAR said.
The report also said unqualified and potentially corrupt actors continue to operate in key Afghan anti-corruption institutions.
The US Agency for International Development (USAID) obligated $27 million to provide technical assistance and internal anti-corruption training to the High Office of Oversight and Anti-Corruption, SIGAR said.