Story highlights Faraj al-Shibli is the second Benghazi suspect to surface in recent weeks

His body was found in an eastern Libya town

Last month, U.S. commandos captured Ahmed Abu Khattalah, who is charged in the attack

Four Americans died in the 2012 attack on the U.S. diplomatic compound in Benghazi

Tripoli, Libya (CNN) A man once detained by Libyan officials and interviewed by the FBI over suspected links to the deadly 2012 attack on the U.S. diplomatic compound in Benghazi, Libya, has turned up dead.

Faraj al-Shibli, whose name is also spelled Chalabi, was last seen in the custody of a local militia in Marj two days ago, a Libyan source said. His body was found Monday in the eastern Libyan town.

He's the second Benghazi suspect to surface in recent weeks. U.S. forces arrested suspected attack mastermind Ahmed Abu Khattalah last month.

Here's what CNN has previously reported about those suspected of involvement in the attacks. With the exception of Abu Khattalah, it's unknown if any have been charged in connection with the Benghazi attack. The charges remain under seal.

Al-Shibli -- The Libyan government -- The Libyan government took al-Shibli into custody in March 2013 in connection with the Benghazi attack. The FBI was able to question him during that detention. Al-Shibli was no longer in custody as of May 2013, according to a Libyan source briefed on the case. Libyan officials have not explained why he was released. It's not clear what role he may have played in the attack, or if he's among the suspects named in sealed federal charges brought last year. Al-Shibli was a member of the Libyan Islamist Fighting Group, a militant organization that tried to overthrow the government of late Libyan leader Moammar Gadhafi in the mid-1990s. That regime named him as a suspect in the murder of a German counterintelligence official and his wife, who were killed in the Libyan town of Sirte in 1994. Libyan authorities also issued an arrest warrant for former al Qaeda leader Osama bin Laden in connection with the crime.