Former Afghan president Ashraf Ghani almost certainly did not flee Kabul as it fell to the Taliban with millions of dollars in stolen cash, a US government watchdog's report said Monday.

The Special Inspector General for Afghanistan Reconstruction (SIGAR) report, which will be published on Tuesday, is an interim document, as the office is still awaiting answers to questions sent to Ghani.

First reported on by Politico, it interviews witnesses as well as officials who were in the helicopter convoy with Ghani as they hastily fled the Presidential Palace in Kabul while the Taliban marched into the capital on August 15, 2021.

In subsequent days, multiple reports suggested that Ghani and the other officials took up to $169 million in Afghan government money with them. Ghani has always fiercely denied these claims.

"Although SIGAR found that some cash was taken from the grounds of the palace and loaded onto these helicopters, evidence indicates that this number did not exceed $1 million and may have been closer in value to $500,000," the report states.

It based that assessment heavily on interviews with the witnesses and officials involved, all of whom said they saw no signs of such large amounts of cash on the helicopters already overloaded with people fleeing for their lives.

"$169 million in hundred dollar bills, stacked end to end, would form a block 7.5 feet (2.3 meters) long, 3 feet wide, and 3 feet tall... This block would have weighed 3,722 pounds, or nearly two tons," SIGAR noted, adding that witnesses reported "minimal luggage" on the helicopters, which had no cargo holds.

Instead one official carried around $200,000, another carried some $240,000 and others had "$5,000 to $10,000 in their pockets... No one had millions," one former senior official told SIGAR.

"If true, this puts the total amount of cash on board the three helicopters at approximately $500,000, with $440,000 belonging to the Afghan government," the report said.

"SIGAR also identified suspicious circumstances in which approximately $5 million in cash was allegedly left behind at the presidential palace," the report added.

It was not clear where the money came from or what it was for, "but it was supposedly divided by members of the Presidential Protective Service after the helicopters departed but before the Taliban captured the palace," it said.

The report said there appears to have been "ample opportunity and effort to plunder Afghan government coffers."

But, the watchdog added, it "does not have sufficient evidence to determine with certainty whether hundreds of millions of dollars were removed from the country by Afghan officials as the government collapsed or whether any stolen money was provided by the United States."