A U.S. newspaper reports the Bush administration repeatedly discouraged efforts to investigate the 2001 mass killings of Taliban prisoners by the militia of an American-backed warlord.

The New York Times reports the FBI, State Department and Red Cross pushed for a probe, but the White House failed to act because the warlord, General Abdul Rashid Dostum, was being paid by the CIA at the time of the killings.

Dostum and his fighters are accused of killing hundreds, and perhaps thousands of Taliban prisoners who surrendered after the 2001 invasion of Afghanistan.  Authorities believe the bodies were placed in a mass grave found in Dasht-e-Leili in 2002.

The report says the Bush White House was also worried about undermining U.S.-backed Afghan President Hamid Karzai, who named Dostum to his defense team.

The U.S.-based Physicians for Human Rights called for a criminal probe into the alleged massacre Friday.

The group says it has obtained U.S. government documents that show as many as 2,000 Taliban fighters were suffocated in container trucks by Dostum's forces and buried in the Dasht-e-Leili desert in November of 2001.