With the recent death of Usama bin Laden, the life of another Al Qaeda-linked radical Muslim cleric is taking on greater significance, and documents obtained exclusively by Fox News and its Specials Unit shed new light on his stint as a guest speaker at the Pentagon just months after the Sept. 11 terror attacks.

American cleric Anwar al-Awlaki, the first American on the CIA’s kill or capture list, is still considered a grave threat to U.S. national security. He now is hiding out in Yemen, where earlier this month a U.S. missile attack tried to kill him and his followers.

The scene was much different on February 5, 2002, when the radical imam was invited to and attended the Pentagon event.

Fox News obtained new documents through a Freedom of Information Act request as part of a year-long investigation called "Fox News Reporting: Secrets of 9/11." An internal Department of Defense email that announced the event with Awlaki also laid out other details, like a proposed menu including pork, which is prohibited for Muslims. The email states "the chef will create something special for vegetarians."

Tune in Friday to "Fox News Reporting: Secrets of 9/11," debuting at 10 p.m. ET.

More On This...

The documents show that more than 70 people were copied on the invitation, which originated in the Defense Department’s Office of the General Counsel. It is home to the Pentagon's top lawyer.

"I have reserved one of the executive dining rooms for February 5th, which is the date he (Awlaki) preferred," a defense department lawyer wrote in the e-mail announcing the event.

"He (Awlaki) will be leaving for an extensive period of time on February 11th."

The e-mail states that New Mexico born al-Awlaki was the featured guest speaker on “Islam and Middle Eastern Politics and Culture."

The Defense Department lawyer who vetted the imam wrote that she "had the privilege of hearing one of Mr. Awlaki's presentations in November and was impressed by both the extent of his knowledge and by how he communicated that information and handled a hostile element in the audience."

Fox News reached out to the Office of General Counsel for comment on the event in 2002 and the vetting process, but the Defense Department said it did not have additional information to provide.

In October 2010, Fox News and its Specials Unit broke the al-Awlaki lunch story when its investigative team obtained documents, including an FBI interview conducted after the Fort Hood shooting in November 2009, that stated Awlaki was taken to the Pentagon as part of the military's outreach to the moderate Muslim community in the immediate aftermath of the attacks.

Click here to read the report.

Al-Awlaki, a dual U.S. and Yemeni national, was interviewed at least four times by the FBI in the first eight days after the Sept. 11 attacks because of his ties to the three hijackers Nawaf al-Hazmi, Khalid al-Mihdhar and Hani Hanjour. They were three of the five hijackers of American Airlines Flight 77, which was flown into the Pentagon. Apparently, none of the FBI's information about Awlaki, his ties to the hijackers or his history of soliciting prostitutes was shared with the Pentagon.

In October 2010 an Army spokesman insisted that it was not an Army event.

"The Army has found no evidence that the Army either sponsored or participated in the event described in this report," spokesman Thomas Collins said.

Collins also noted that the FBI document, dated November 2009, referred to the "Office of Government Counsel" but should read "Office of General Counsel."

Collins said he believed the event was sponsored by the Office of the Secretary of Defense (OSD). This is consistent with the new documents obtained by Fox because the General Counsel's office falls under OSD.

A former high-ranking FBI agent told Fox News that at the time Awlaki went to lunch at the Pentagon, there was tremendous "arrogance" about the vetting process at the Pentagon.

"They vetted people politically and showed indifference toward security and intelligence advice of others," the former agent said.

National Correspondent Catherine Herridge's first book "The Next Wave: On the Hunt for al Qaeda's American Recruits" will be published by Crown on June 21st. It draws on her reporting for Fox News into al-Awlaki, his new generation of recruits, and it explores why information about the cleric was withheld from government investigators.