With the 10th anniversary of the 9/11 attacks only a month away, former CIA Director George Tenet and two former top aides are fighting back hard against allegations that they engaged in a massive cover-up in 2000 and 2001 to hide intelligence from the White House and the FBI that might have prevented the attacks.

The source of the explosive, unproved allegations is a man who once considered Tenet a close friend: former White House counterterrorism czar Richard Clarke, who makes the charges against Tenet and the CIA in an interview for a radio documentary timed to the 10th anniversary next month. Portions of the Clarke interview were made available to The Daily Beast by the producers of the documentary.

In the interview for the documentary, Clarke offers an incendiary theory that, if true, would rewrite the history of the 9/11 attacks, suggesting that the CIA intentionally withheld information from the White House and FBI in 2000 and 2001 that two Saudi-born terrorists were on U.S. soil—terrorists who went on to become suicide hijackers on 9/11.

Clarke speculates—and readily admits he cannot prove—that the CIA withheld the information because the agency had been trying to recruit the terrorists, while they were living in Southern California under their own names, to work as CIA agents inside Al Qaeda. After the recruitment effort went sour, senior CIA officers continued to withhold the information from the White House for fear they would be accused of “malfeasance and misfeasance,” Clarke suggests.

Clarke said that if his theory is correct, Tenet and others would never admit to the truth today “even if you waterboarded them.”

Clarke’s theory addresses a central, enduring mystery about the 9/11 attacks— why the CIA failed for so long to tell the White House and senior officials at the FBI that the agency was aware that two Al Qaeda terrorists had arrived in the United States in January 2000, just days after attending a terrorist summit meeting in Malaysia that the CIA had secretly monitored.

In a written response prepared last week in advance of the broadcast, Tenet says that Clarke, who famously went public in 2004 to blow the whistle on the Bush White House over intelligence failures before 9/11, has “suddenly invented baseless allegations which are belied by the record and unworthy of serious consideration.”

The CIA insisted to the 9/11 Commission and other government investigations that the agency never knew the exact whereabouts of the two hijackers, Nawaf al-Hazmi and Khalid al-Mihdhar, inside the U.S.—let alone try to recruit them as spies.

Agency officials said the CIA's delay in sharing information about the two terrorists was a grave failure, but maintained there was no suggestion of deception by CIA brass. Tenet has said he was not informed before 9/11 about Hazmi and Mihdhar's travel to the U.S., although the intelligence was widely shared at lower levels of the CIA.

The 9/11 Commission investigated widespread rumors in the intelligence community that the CIA tried to recruit the two terrorists—Clarke was not the first to suggest it—but the investigation revealed no evidence to support the rumors. The commission said in its final report that "it appears that no one informed higher levels of management in either the FBI or CIA" about the two terrorists.

But in his interview, Clarke said his seemingly unlikely, even wild scenario—a bungled CIA terrorist-recruitment effort and a subsequent cover-up—was “the only conceivable reason that I’ve been able to come up with” to explain why he and others at the White House were told nothing about the two terrorists until the day of the attacks.

“I’ve thought a lot about this,” Clarke says in the interview, which was conducted in October 2009. He said it was fair to conclude “there was a high-level decision in the CIA ordering people not to share information.” Asked who would have made the order, Clarke replies, “I would think it would have been made by the director,” referring to Tenet.

Clarke, now a security consultant and bestselling author, has hinted in his writings in the past that there may have been a CIA cover-up involving Hazmi and Mihdhar, although he has never made such direct attacks on Tenet and others at the CIA by name.

He did not reply to requests from The Daily Beast to expand on his comments or to explain why he has not repeated them publicly since the 2009 interview. The documentary’s producers, FF4 Films, said they had been in contact with Clarke this month and that he stood by his remarks in the broadcast.

The producers, John Duffy and Ray Nowosielski, had previously made a well-reviewed film documentary, Press for Truth (www.911pressfortruth.com), on the struggle of a group of 9/11 victims' families to force the government to investigate the attacks.

In finishing the radio documentary, they recently supplied a copy of Clarke's comments to Tenet, who joined with two of former top CIA deputies—Cofer Black, who was head of the agency's counterterrorism center, and Richard Blee, former head of the agency's Osama Bin Laden unit—in a statement denouncing Clarke.

“Richard Clarke was an able public servant who served his country well for many years,” the statement says. “But his recently released comments about the run-up to 9/11 are reckless and profoundly wrong.”

“Clarke starts with the presumption that important information on the travel of future hijackers to the United States was intentionally withheld from him in early 2000. It was not.”

The statement continued. “Building on his false notion that information was intentionally withheld, Mr. Clarke went on to speculate—which he admits is based on nothing other than his imagination—that the CIA might have been trying to recruit these two future hijackers as agents. This, like much of what Mr. Clarke said in his interview, is utterly without foundation.”

Clarke, who led governmentwide counterterrorism efforts from the White House during the Bush and Clinton administration, has said in the past that he was astonished to learn after 9/11 that the CIA had long known about the presence of Hazmi and Mihdhar inside the United States.

“To this day, it is inexplicable why, when I had every other detail about everything related to terrorism, that the director didn’t tell me, that the director of the counterterrorism center didn’t tell me,” Clarke said in the interview for the documentary, referring to Tenet and Cofer Black. “They told us everything—except this.”

He said that if he had known anything about Hazmi and Mihdhar even days before 9/11, he would have ordered an immediate manhunt to find them—and that it would have succeeded, possibly disrupting the 9/11 plot.

“We would have conducted a massive sweep,” he said. “We would have conducted it publicly. We would have found those assholes. There’s no doubt in my mind, even with only a week left. They were using credit cards in their own names. They were staying in the Charles Hotel in Harvard Square, for heaven’s sake.” He said that “those guys would have been arrested within 24 hours.”