Amnesty International and Palestinian cultural institutions have launched an appeal for help for 23-year-old Palestinian circus performer and teacher Mohammed Abu Sakha - who in addition to being a clown is a member of a brutal Communist terror organization.
Abu Sakha was arrested on December 14 and held since January in administrative detention, an emergency measure introduced by the British Mandate under which Israel can hold suspects without trial for periods of six months, renewable indefinitely.
Amnesty acknowledged that Israel has revealed Abu Sakha is a member of the Popular Front for the Liberation of Palestine (PFLP), an outlawed terrorist organization.
One of the most infamous attacks by the group was the 2001 assassination of Tourism Minister Rehavam "Gandhi" Ze'evi, which was committed by four PFLP terrorists in Jerusalem.
The IDF refused to comment to AFP regarding Abu Sakha's detention.
The Palestinian Performing Arts Network (PPAN), representing artists and cultural institutions, said it was "deeply concerned" over the detention of Abu Sakha, who since 2008 has been part of the Palestinian Circus School in Bir Zeit, first as a student and later as a clown and teacher.
PPAN called on artists and cultural organizations "to raise awareness of Israel's illegal policy of administrative detention" and pressure Israel to release Abu Sakha.
Amnesty also called to pressure Israel ahead of a military court hearing of Abu Sakha's appeal against his detention, scheduled for March 21.
Abu Sakha's mother was allowed to visit him once in the Megiddo prison in northern Israel, where according to Amnesty he was entertaining his fellow inmates to help the time pass, in a sign that he is not in harsh jail conditions - indeed Arab terrorists receive numerous comforts in prison including programs for free education.
Administrative detention is intended to allow authorities to hold suspects while continuing to gather evidence, with the aim of preventing further attacks in the meantime.
In some cases the detention is used when a sensitive Arab source has given concrete information and the authorities want to protect the identity of the informant.
AFP contributed to this report.