A member of the extremist Neturei Karta Haredi sect was arrested Wednesday after he met suspected Palestinian terrorists in Jenin.
The 38-year-old man was suspected of meeting with members of the Islamic Jihad in Jenin, and violating the law prohibiting entry into the Palestinian Authority-controlled areas.
The Israel Police also suspect other members of the extreme sect who attended the meeting.
Footage of the suspect's visit to Jenin was posted on social media earlier this week, and an investigation was subsequently opened.
Police asked the Jerusalem Magistrate's Court on Thursday to remand the man to custody, claiming that the acts attributed to him were severe and that they were concerned he may obstruct the investigation.
The group said that their visit was to stand in solidarity with the Palestinians in the face of the so-called Israeli oppression.
"We are Palestinian Jews, we want to live under the Palestinian flag and not the Israeli flag, in one country which is the Palestinian state," a member of the group, which refuses to recognize Israel for religious reasons, said.