The Justice and State departments are now citing a year-old FBI investigation and a future criminal prosecution to block access to survivors of last year’s Benghazi terror attack.

In an Oct. 28 letter to Sen. Lindsey Graham, R-S.C.,the State Department’s Assistant Secretary for Legislative Affairs, Julia Frifield, refers to "significant risks" and "serious concerns about having the survivors of the attack submit to additional interviews."

Graham has been asking since last year for the FBI’s transcripts of interviews with State Department and CIA survivors who were evacuated to Germany after the Sep.11 attack on the U.S. consulate.

He and other Republicans believe the transcripts will show the survivors told the FBI it was a terrorist attack and made no mention of a video or anti-U.S. demonstration at the consulate.

This intelligence was likely available to the president, his national security team and U.N. Ambassador Susan Rice, who five days after the assault blamed it on an anti-U.S. demonstration and inflammatory video.

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"You can't hide behind a criminal investigation," Graham told reporters during a news conference on Capitol Hill. "That's not a good reason to deny the Congress witness statements 48 hours after the attack."

The House Committee on Oversight and Government Reform and its Republican Chairman, Darell Issa, recently interviewed – against the Justice Department’s wishes -- two State Department security agents who have firsthand knowledge of the attack, leading one Democratic lawmaker to predict the move would create inconsistencies and complicate a trial.

"As a prosecutor, you never want your witnesses to be interviewed by multiple sources. It just lends itself to the possibility of unintentional conflicts within their statements," Rep.Adam Schiff, D-Calif., a member of the House Intelligence Committee, told Fox News.

"It concerns me that that was not a higher priority for the chairman, to make sure that we could bring these people to justice, than to carry on this political exercise."

But waiting for a criminal prosecution and appeal to be wrapped up, according to Republicans, doesn't pass the sniff test.

"So we are going to wait three years when we had a terrorist attack, which is very different than your average criminal case that Senator Graham talked about, to get the truth and think about what we know to prevent future terrorist attacks?" asked Sen.Kelly Ayotte, R-N.H.

As Rep. Frank Wolf, R-Va., renewed his call for a select committee, lawmakers also cited the reporting of Fox News, followed by CBS’ “60 Minutes,” that the main Benghazi suspects have strong ties to Al Qaeda senior leadership.

At the same time, another Republican turned the tables on the media and its apparent lack of curiosity about Ambassador Chris Stevens' final days.

"Does it bother you whether or not you know why Chris Stevens was in Benghazi?" asked Trey Gowdy, R-S.C. "Do you know why we were the last flag flying in Benghazi after the British had left and the Red Cross had been bombed? Do you know why requests for additional security were denied?"

Rep. Mike McCaul, R-Tex.,chairman of the House Committee on Homeland Security and a senior member of the House Foreign Affairs Committee, sent a letter to Secretary of State John Kerry with 84 congressional signatures asking why his department was not offering a reward for tips leading to the Benghazi suspects.

The “Rewards for Justice” program, described on the State Department’s own website as a valuable tool in counter-terrorism cases, offers millions of dollars for information about suspects who are not accused of murdering Americans.

Yet there is no reward for information leading to those who murdered Stevens, Foreign Service officer Sean Smith, and former Navy SEALs Tyrone Woods and Glen Doherty.

Kerry's staff refuses to discuss it. "I don't have anything new for you on the Al Qaeda suspects from Benghazi," State Department spokesman Jen Psaki told Fox News. .