KABUL, Afghanistan — Persistent political interference has hampered efforts to unravel the colossal fraud at Kabul Bank, with President Hamid Karzai and a small panel of his top aides actually dictating to prosecutors who should be charged and who should not, according to Afghan and Western officials and the results of a public inquiry into the scandal.

According to a report, which was prepared by an independent corruption watchdog commission at the behest of the International Monetary Fund and which is to be released Wednesday, Mr. Karzai’s aides called in prosecutors to tell them who would be indicted in the fraud and collapse of Kabul Bank, even specifying what charges should be brought. A senior Afghan official with knowledge of the decisions, speaking on the condition of anonymity, said that Mr. Karzai was among those directly making the decisions.

The president had previously signaled that he would do so. Ahmad Qaderi, a senior official at the attorney general’s office of Afghanistan, acknowledged the president’s role last year, telling reporters, “President Karzai will decide which accounts should go into receivership and which into the courts.”

The indictments in the case, in June, were hailed as important first steps in finally bringing accountability for officials who profited from a fraud scheme that involved hundreds of millions of dollars and brought down Kabul Bank in 2010. But some were troubling: the indictment list included prominent Afghan financial regulators who were trying to untangle the mess at the bank and had often clashed with Mr. Karzai’s administration, according to the report and Afghan officials.