An FBI mole who provided valuable intelligence on al Qaeda and met with Osama bin Laden was lured away from the FBI to work for the CIA, but was killed by al Qaeda operatives in Bosnia who suspected he was an informant, NBC News has learned exclusively.

The informant, a Sudan-born driver and confidante to “Blind Sheikh” Omar Abdel-Rahman, the radical Muslim cleric who allegedly masterminded the first attempt to take down the World Trade Center, had been the sole human asset providing first-person information about al Qaeda in the mid-1990s as the terror group gained strength around the globe.

According to sources familiar with the management of the mole, the FBI recruited him in 1993 because he was a known associate of the Blind Sheikh.

Sheik Omar Abdel-Rahman, the alleged mastermind of the first World Trade Center bombing. Ted Thai / Time Life Pictures via Getty Images

The Egyptian-born Sheikh had been an FBI target since at least Nov. 5, 1990, when one of his followers, El Sayyid Nosair, shot and killed radical Rabbi Meir Kahane in a Manhattan hotel. After the shooting, boxes of information were found in Nosair’s apartment that hinted at a larger conspiracy.

Under pressure, the Sheikh moved some of his operations from the New York area to Los Angeles, where the future mole was living. The mole became the Sheikh’s driver. That’s when the FBI first noticed him, and started the process that would turn him into an informant.

In early 1993, the Immigration and Naturalization Service tipped the FBI to the driver’s identity, and the FBI found that he was on a terrorism watch list. The INS then tried to deport the driver, only to discover that the driver’s status as a possible Islamic militant made it hard to find a country that would accept him.

Jordan agreed to take him, but then threw him in jail for three months. The driver wound up in Yemen, where the FBI began to reel him in.

Though the chronology is unclear, by around this time terrorists had mounted their first attack on New York’s World Trade Center. On Feb. 26, 1993, a truck filled with 1,500 pounds of explosive detonated in an underground garage, killing six people but failing to take down the twin towers.

The FBI increased its focus on the Sheikh and his associates, who were suspected of involvement. In Yemen, the FBI agent who would later become the driver’s handler – Bassem Youssef, the bureau’s highest ranking Arabic speaker – made his first approach. According to sources, he introduced himself to the driver not as an agent, but as a friend who could help reunite the driver with his family in California, via personal connections with an important L.A. judge.

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The bureau also obtained warrants to listen to phone calls to and from the driver’s home, including conversations with the Sheikh. And it began to work on the driver’s wife, who became a cooperating source.

The driver, however, still didn’t know he was talking to the FBI. But after subsequent meetings with Youssef and other agents in Rome and Brussels, he learned the truth, and agreed to provide information, said sources. He started talking about a terror group called al Qaeda. In Brussels, he passed a polygraph test, and then produced a dozen authentic U.S. and Canadian passports in which the original pictures had been replaced with the pictures of al Qaeda operatives. The operatives had used the passports to crisscross Europe and spread the message of jihad.

The driver was also able to arrange a trip to his home country of Sudan for a meeting with one of the Sheikh’s associates, a little-known Saudi-born terror leader named Osama bin Laden.

“Bin Laden was not bin Laden then,” said one Justice Department official. “He was not that hard to get to.”

In Sudan, bin Laden told the mole that he had “picked out” a Masonic Lodge in Los Angeles for an “explosion.” The mole also told the FBI that the Sheikh said, “If you need any money, you go to Osama directly and tell him I sent you.” It is not known whether the source tried to solicit funds from bin Laden.

Back in the U.S., the Blind Sheikh was arrested along with nine followers on June 24, 1993. He was later convicted of conspiracy for planned attacks on American landmarks, and sentenced to life in prison.

The informant continued working for the FBI after the Sheikh’s arrest, said sources. But the mole’s success had piqued the interest of another U.S. agency, the CIA. In 1994, a civilian female working for the CIA was able to convince the informant, with the help of a large sum of money, to work for the CIA instead of the FBI.

In 1994 or 1995, the CIA dispatched the informant to Bosnia, where jihadis were aiding Bosnia’s Muslim majority in a war against Serbian forces.

The FBI did not know at the time that its informant had started working for the CIA, or why he had disappeared. His former handler, Bassem Youssef, who by then was working undercover in Los Angeles as a supposed member of al Qaeda, began asking his al Qaeda sources what had become of the driver.

They told Youssef that the driver had gone to Bosnia, and that al Qaeda operatives there had killed him because they believed that he was a mole for the CIA. Later, Youssef was able to confirm that the al Qaeda operatives’ suspicions were justified, and that the driver had been working for the CIA.

The existence of the informant was first revealed during courtroom testimony in 2010, as part of a discrimination suit filed by Bassem Youssef against the FBI. Youssef accused the bureau of passing him over for promotion despite his skills.

Testifying on Youssef’s behalf, former assistant special agent in charge of the FBI’s L.A. office Ed Curran revealed that Youssef had developed the Blind Sheikh’s driver as an informant.

“It was the only source I know in the bureau where we had a source right in al Qaeda, directly involved,” Curran told the court, according to excerpts of testimony published by the Washington Times. He also testified that the informant was “tight, close” with al Qaeda leadership.

The Washington Times was the first media outlet to report on Curran’s revelation, and noted that the bureau had declined to tell the 9/11 Commission, which investigated al Qaeda’s 2001 attack on the World Trade Center, about the al Qaeda informant’s existence.

Sources told NBC News, however, that they weren’t sure the informant was relevant to the 9/11 Commission, because by 2001 his short, albeit productive, relationship with the U.S. government – and his life – had been over for six years.

In a statement, the FBI said that the FBI “made all relevant information available to the 9/11 Commission.”

The CIA did not immediately respond to a request for comment.

Bassem Youssef is still with the FBI and continues to pursue his discrimination suit.