Even as the White House labels Benghazi a "phony scandal," a raft of new allegations and concerns is once again bringing the controversy back to the forefront in Washington.

Fox News has learned that at least five CIA employees were forced to sign additional nondisclosure agreements this past spring in the wake of the Benghazi attack. These employees had already signed such agreements before the attack but were made to sign new agreements aimed at discouraging survivors from leaking their stories to the media or anyone else.

CNN has also reported that dozens of people working for the CIA were in Benghazi on the night of the attack, and that employees are being intimidated into staying silent.

CIA spokesman Dean Boyd pushed back on the claims in a written statement released Friday.

"CIA employees are always free to speak to Congress if they want to and there is an established process to facilitate such communication on a confidential basis. The CIA enabled all officers involved in Benghazi the opportunity to meet with Congress," he said. "We are not aware of any CIA employee who has experienced retaliation, including any non-routine security procedures, or who has been prevented from sharing a concern with Congress about the Benghazi incident."

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But the claims have fueled concerns by lawmakers that, while the government is spending much energy on keeping Benghazi personnel quiet, not enough progress has been made in tracking down those actually responsible for the strike.

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Lawmakers pointed to a report by CNN earlier this week in which Ansar al-Sharia leader Ahmed Abu Khattala told the network that nobody from the American government has contacted him. Ansar al-Sharia is a militant group in the region considered of high interest in connection with the attack.

"Even the investigative team did not try to contact me," he told CNN.

Lawmakers penned a letter earlier this week to newly confirmed FBI Director James Comey urging him to aggressively identify and pursue the suspects.

"It has been more than 10 months since the attacks. We appear to be no closer to knowing who was responsible today than we were in the early weeks following the attack," they wrote. "This is simply unacceptable."

Some in Congress continue to press for a select committee to investigate the Sept. 11 attacks. Rep. Steve Stockman, R-Texas, announced on Thursday that he plans to try and force a vote in Congress on creating such an investigative panel. House rules could make this an uphill effort for Stockman.

Separately, House Oversight and Government Reform Committee Chairman Darrell Issa, R-Calif., on Thursday issued two new subpoenas to the State Department for documents on Benghazi.

The White House earlier this week claimed it considers the controversy over Benghazi -- specifically over how officials initially described the nature of the attack -- as "phony."

But the details about the lengths to which the government is going to keep people quiet has raised additional questions.

The CNN report said some CIA operatives are being forced to take "frequent, even monthly" lie detector tests. They're reportedly trying to root out who is talking to reporters or members of Congress.

"You have no idea the amount of pressure being brought to bear on anyone with knowledge of this operation," one source was quoted as saying.

The nature of that operation is unclear to this day. One source told CNN that 21 Americans had been working at the CIA annex in Benghazi at the time of the attack. Initially, the compound was merely described as a diplomatic consulate.

Fox News' Jennifer Griffin contributed to this report.