Key documents relating to the Obama administration’s secret negotiations with Iran, including a $1.7 billion cash payment, are being stored at a highly secure site on Capitol Hill, preventing the public and many in Congress from accessing them, according to multiple sources who described the situation to the Washington Free Beacon.

The documents are not technically classified but are being kept in a "secure reading space" where the majority of congressional officials cannot access them. Those cleared are forced to relinquish their cellular devices and are barred from taking notes, undermining the ability of staffers to brief their lawmakers on the contents, according to the sources.

Sources further disclosed that joint U.S.-Iranian signatures across the three documents add up to a package deal between Washington and Iran’s Intelligence Ministry, the country's internal spy agency. Sources familiar with a closed-door January briefing by senior Obama administration officials told the Free Beacon they were informed the United States negotiated with "the Iranian intelligence apparatus."

The terms of the arrangement—which was signed by Special Presidential Envoy Brett McGurk—had Iran releasing several U.S. hostages and obligated Washington to pay Tehran $1.7 billion in cash, removed international sanctions on a key financial node of Iran’s ballistic missile program, and dropped charges against 21 Iranian operatives linked to terrorism.

"There are three of them [agreements], and one specifically relates to the $1.7 billion [payment] and is a commitment of the U.S. to make arrangements to transfer the money," said one congressional official familiar with the agreements.

A second document "lays out the commitments regarding Iranians that the U.S. was going to pardon, as well as the release of [imprisoned] Americans," the source explained.

A third document "relates to assurances" the United States would allow international sanctions to be dropped on Iran’s Bank Sepah, a bank the Treasury Department described in 2007 as the "linchpin of Iran’s missile procurement."

Multiple sources told the Free Beacon all three documents are part of one package deal. Each document was initially dated Jan. 16, but that was subsequently "crossed out and the 17th was scribbled in," according one congressional source who spoke to the Free Beacon.

"They were all signed at the same time and ties it to the hostage release," the source said. It further debunks claims made for months by the Obama administration that the negotiations over each concession were kept separate.

A second senior congressional source familiar with the contents of these secret documents told the Free Beacon that they provide proof that each of these three concessions to Iran was bound up in the hostage release.

"If it looks like ransom and sounds like ransom, it’s probably ransom," the source said. "Why else would Brett McGurk deal with his Iranian counterparts and sign agreements on all these seemingly unrelated issues on the same day and in the same place if they weren’t connected?"

A third senior congressional official told the Free Beacon that officials were never notified by the Obama administration that these documents were partially being made available. The source speculated the administration did this to avoid rigorous oversight of its diplomacy with Iran.

"The State Department knows that its Iran policy is embarrassing and often semi-illegal, so it hides documents related to Iran," the official said. "State delays publication, refuses to answer questions, and puts extra restrictions preventing the Hill from even accessing the materials."

The handling of these documents is similar to the Iran deal itself, which the Free Beacon first disclosed could only be viewed by congressional officials in a highly classified manner.

The Free Beacon disclosed on Tuesday that the administration misled journalists and lawmakers for more than nine months about a secret agreement lifting international sanctions on Bank Sepah.

A State Department official declined to provide the Free Beacon with the name and affiliation of the Iranian official or officials who took part in negotiations with McGurk. The State Department also would not provide information about the process by which Congress can view these documents.

"As part of the JCPOA [Joint Comprehensive Plan of Action] negotiations, the United States made the determination that it would remove Bank Sepah from our Specially Designated Nationals and Blocked Persons List (SDN List) on Implementation Day," the State Department official told the Free Beacon.

"In general, we are committed to ensuring that Congress has documents and information it may need to conduct effective oversight, and have transmitted these in a fashion that both protects sensitive information while giving all Members the ability to review them," the official said.