Former Al Qaeda leader Osama bin Laden
Former Al Qaeda leader Osama bin Laden Flash 90

Iran released five top Al Qaeda terrorists in a swap with the terror group's branch in Yemen, an American official revealed Thursday night - including one with a $5 million bounty on his head. 

The five were released in March 2015, the official said, possibly in exchange for an Iranian diplomat being held in the embattled country.

According to the New York Times, the five prisoners included:

  • Saif al-Adl, a senior member of Al Qaeda’s ruling body, the Shura Council, who replaced arch-terrorist Osama bin Laden after his assassination in 2011. Adl, who functions as the terror group's master of operations, is on the FBI's Most Wanted Terrorist; he was indicted in the 1998 bombings of the US embassy in East Africa. A $5 million bounty has been offered for his capture.
  • Abu Mohamed al-Misri, an Egyptian who helped Al Qaeda carry out major attacks before September 11, 2001;
  • Abul Qassam, a Jordanian who served as the deputy leader to notorious Al Qaeda in Iraq leader Abu Musab al-Zarqawi, whose group would eventually become Islamic State (ISIS);
  • Abdul Khayr al-Misri, Egyptian, formerly head of Al Qaeda's foreign relations;
  • Sari Shibab, a Jordanian terrorist for the group. 

Al Qaeda expert Michael S. Smith II of Kronos Advisory revealed to the Times that the five had been moved to Iran to ensure their safety following the September 11 attacks; Al Qaeda believed the change would afford them greater security and anonymity.

It is unclear when the five were taken into Iranian custody, but all apparently had maintained contact with Al Qaeda from behind prison walls. 

The Iranian government has denied the swap ever took place, despite a Sky News report exposing the deal earlier this week.