Israeli police are holding an Israeli professor and peace activist on charges he was in contact aboard with members of an organization, presumably Palestinian, deemed illegal under Israeli law, according to reports yesterday from Israel.

The prisoner, Uri Davis, was picked up at Lod airport outside Tel Aviv on Thursday night and jailed in Haifa, then brought before a judge Friday for a hearing on a police request that he be held for an additional eight days' interrogation, the reports said.

The motion was granted and Davis is undergoing questioning on the charges, which are believed to concern alleged contacts in Europe with Palestine Liberation Organization members or officials, according to the reports from his wife Toshi and his lawyer, Lea Tsemel of Jerusalem.

Israeli law bars association with groups such as the PLO that are illegal in Israel even if the contacts occur outside Israel in countries where the groups are legal, such as in European countries.

In apparently connected arrests, Israeli police also took into custody 15 Arab students and former students from Hebrew University, Tel Aviv University and Beersheba University, sources in Washington quoted Tsemel as saying. The 15 have worked with Davis and other peace activists in opposition to Israeli policy on Arab citizens of Israel.