Iran is estimated to have spent at least $37.4 million in recent U.S. cash payments to fund its global terrorism operation, including organizations responsible for the murder of U.S. citizens, according to new research provided to the Washington Free Beacon by analysts.

The recent $1.7 billion cash payment to Iran—which is being described by many in Congress as a ransom payment to the Islamic Republic—will be used in part to fund Iran’s leading military organization, the Islamic Revolutionary Guard Corps (IRGC), which is responsible for orchestrating terror attacks that have killed Americans.

The new research comes amid a growing scandal over the Obama administration’s decision to hand Iran billions in cash as part of an effort to secure the release of several U.S. hostages earlier this year.

Leading lawmakers now suspect that the IRGC played a key role in assuming control of this cash, which the White House has admitted to putting directly in Iranian hands, the Free Beacon disclosed Monday evening.

When viewed in light of Iran’s current spending levels, it is expected the Islamic Republic will use at least $37.4 million of this $1.7 billion to fund IRGC operations, which have led to bloody battles in Syria and terrorist attacks across the globe, according to the American Action Forum, a non-profit research organization headed by a former top congressional official.

"Applying the official spending levels to the U.S. payment to Iran, the $1.7 billion would mean $37.4 million for the IRGC," according to research published by Rachel Hoff, AAF’s director of defense analysis. "Paying ransoms in exchange for Americans held abroad is one bad policy—indirectly funding terrorism is another."

AAF has determined based on public reports by Iran that the country spends 3.4 percent of its total budget on defense needs, though some experts estimate the number is even higher.

At least "65 percent of that funding [goes] to the Islamic Revolutionary Guard Corps (IRGC), the Iranian elite paramilitary force," according to AAF. "That works out to 2.2 percent of Iran’s total budget for the IRGC, which actively supports terrorist organizations throughout the Middle East. It is unlikely that Iran accurately reports its military or paramilitary spending, but the reported budget figures are useful as a baseline."

These latest estimates are likely to draw further outrage on Capitol Hill, where lawmakers have launched several investigations into the circumstances surrounding the $1.7 billion payment.

While the Obama administration has been forced to disclose some details about the cash payment, it withheld key information from Congress, including the names and affiliations of the Iranian officials who assumed control over the money when it was handed off earlier this year in Europe.

New admissions by the Obama administration that American officials physically handed some $1.7 billion in cash to the Iranian government are fueling a congressional investigation into still-hidden details surrounding the deal.

Lawmakers suspect the Obama administration may have dealt with members of the IRGC and officials from its intelligence ministry when carrying out the cash exchange, which coincided with the release by Iran of several U.S. hostages.

The Obama administration recently disclosed to Congress that U.S. officials participated in the handoff of at least $400 million to Iranian officials, but has withheld key details about which parts of the Iranian government assumed control of the cash, according to discussions with multiple sources familiar with the ongoing congressional investigation.

Sources familiar with the matter told the Free Beacon it is possible IRGC members participated in the exchange, raising new questions about the Obama administration’s dealings with an organization responsible for facilitating terrorism and killing U.S. citizens.

"On January 17, Treasury disbursed the payment to an official from the Central Bank of Iran, for transfer to Tehran," the Treasury Department recently informed Congress in a communication obtained first by the Free Beacon. "The funds were under U.S. Government control until their disbursement pursuant to the settlement."

The Obama administration "withdrew the funds from its account as Swiss franc banknotes and the U.S. Government physically transported them to Geneva" prior to the exchange with Iran, according to the letter, which was sent late last week by Treasury Department official Thomas Patrick Maloney in response to questions submitted by Rep. Sean Duffy (R., Wis.).

At least one leading lawmaker told the Free Beacon on Monday that there is little doubt the IRGC played a key role in this cash exchange.

"For the Obama administration to argue that the IRGC was somehow not involved in the U.S. transfer of $1.7 billion—or more—in cash to Iran is totally unconvincing," Rep. Mike Pompeo (R., Kan.), a member of the House Intelligence Committee, told the Free Beacon on Monday. "Given the IRGC’s extensive control of the Iranian economy, and its vast influence with Iran’s regime, it was most likely influential in the set-up and execution of the payment. Like other malicious actors, the IRGC is eager to get its hands on cash to fund its terrorist activities."