Libyan national Abu Anas al-Liby was detained by special operations troops and FBI agents in a weekend raid in Libya. He faces charges stemming from the bombings of the U.S. embassies in Kenya and Tanzania in 1998.
The U.S. government said his arrest was covered under the Authorization for the Use of Military Force measure passed roughly one week after the Sept. 11 attacks. It gives the U.S. president power to use force against anyone suspected of assisting al-Qaida.
Amnesty International said the U.S. government used the "flawed" measure to justify the arrest.
"Abductions of this nature, followed by interrogations during incommunicado detention, undermine the presumption of innocence," the organization said Monday. "[al-Liby's arrest] also undermines Libya's efforts to establish the rule of law at a time when the country is in need of international support to rebuild its institutions significantly weakened by the 2011 armed conflict."
U.S. State Department spokesman Marie Harf noted al-Liby was indicted in a New York court for his ties to al-Qaida. She said Monday the Libyan government was a valuable partner "in fighting shared challenges like the terrorist threat that men like this represent."