An Air Force whistleblower says his team could have provided reinforcements to the Americans under attack in Benghazi in September 2012, contrary to the Obama administration's claims that the military provided the maximum possible support for the embattled diplomatic staff.

"I definitely believe that our aircraft could have taken off and got there in a timely manner, maybe three hours at the most, in order to basically at least stop that second mortar attack and have those guys running for the hills," a man purportedly stationed at Aviano Air Force base in Italy told Fox News on the condition of anonymity.

That's a particularly explosive claim, given that two of the four Americans who died in the attacks were killed in the second wave of attacks, which targeted a CIA annex the morning of Sept. 12. But the whistleblower has not spoken to Rep. Trey Gowdy, R-S.C., who is chairman of the select committee investigating the attacks, because "there are so many ways you can get screwed over" for cooperating with lawmakers.

That frustrates Gowdy, who accused the Obama administration of preventing him from talking to all the relevant witnesses. "As a former federal prosecutor, I find it deeply troubling there are individuals who would like to share their stories, but have not because they are afraid of retaliation from their superiors," he said in a Wednesday evening response to the Fox report. "No one should be afraid of talking to their elected representatives in Congress."

Gowdy allowed that he "cannot vouch for the credibility" of the whistleblower because the committee hasn't interviewed him, but he hailed the new claims as proof that Democrats are wrong to say the investigation is dragging on too long. "Democrats may be content to stick to their pre-ordained conclusions, but the committee has an obligation to determine what can and cannot be substantiated when it comes to the new witnesses we have interviewed and the new evidence we have gathered," he said.

The anonymous whistleblower says he feels "a sense of fault" for not deploying in time to save CIA contractors Glen Doherty and Tyrone Woods, who died in the second assault. "That's a horrible feeling to have when you can help someone, especially when you don't even find out 'til later and you hear that people actually died."