Israel's Supreme Court on Wednesday ordered the immediate expulsion for his "connection with terrorist organisations" of a Polish humanitarian worker held at the country's main international airport for over a week.
"Kamil Qandil should be immediately expelled from Israel because of his connection with terrorist organisations," Chief Justice Asher Grunis said, without elaborating.
Qandil's lawyer said that his client, who has a Palestinian father and Polish mother, was not informed of the allegations against him during the hearing, part of which was held in the presence only of the judges and agents of Shin Bet, Israel's internal security service.
"I have done nothing which could have harmed the state of Israel," Qandil told the court.
Grunis responded that he was "perhaps not aware of his actions."
The Association of International Development Agencies (AIDA), which groups more than 80 organisations, said Qandil was detained on arrival to work on a project to supply water to Palestinians in a part of the southern West Bank under full Israeli control.
"He said that the biggest losers would be the villagers of the south Hebron hills where the project is located and...the Polish taxpayers who fund it," a relative told AFP.
AIDA said in a statement on Tuesday that he works for Polish Humanitarian Action (PHA) and was holding a valid work permit issued by Israel when he was stopped and detained on September 2 at Ben Gurion airport near Tel Aviv on "security grounds."
It said PHA was seeking to refurbish rainwater cisterns on which Palestinian farmers depend for irrigation. Israel has demolished several refurbished cisterns, triggering a diplomatic response from Warsaw, AIDA said.
Shin Bet told Haaretz newspaper on Monday that Qandil was refused entry "due to security information that exists about him."