Abdel Malik Ahmed Abdel Wahab al-Rahabi, bodyguard, 9/11 planner, and possible relative of Osama bin Laden, has been released from Guantanamo Bay and sent to Montenegro, according to the Department of Defense.

Reports are that al-Rahabi had been held at Guantanamo since shortly after it opened and was one of the so-called "Day One" detainees.

The U.S. government was grateful to Montenegro for accepting the former prisoner. "Montenegro now joins other U.S. friends and allies in Europe in accepting multiple detainees for resettlement, bringing us closer to our shared goal of closing the facility," said a State Department official.

The transfer was "consistent with appropriate security and humane treatment measures," the DOD said in a statement.

Barack Obama has been pressing to close Guantanamo ever since he took office. Of the nearly 800 people who have been held there, all but 79 remain, with 29 expected to be released in the coming weeks.