NEW YORK — On May 23, Mordechai Vanunu, whom Amnesty International calls a "prisoner of conscience," was sent to prison for three months, accused of violating the terms of his 2004 release from prison. He has spent 18 years in prison, the first 11 years in solitary confinement.

According to Amnesty International, the 2004 restrictions placed on Vanunu did not include parole, since he had already served his full sentence: "They arbitrarily limited his rights to freedom of movement, expression and association and were therefore in breach of international law."

Vanunu is the former Israeli nuclear technician who, in 1986, revealed details of Israel's nuclear program to the British press. While working as a technician at the Negev Nuclear Research Center, he became increasingly concerned about Israel's nuclear weapons program and its nuclear strategies in case of war. The information he revealed was published by the Sunday Times. He estimated, at the time, that Israel had produced more than 100 nuclear warheads.