JERUSALEM — About a dozen Palestinian businessmen defied the official Palestinian boycott of the Trump administration’s economic conference in Bahrain this week. .
Once there, most of them tried to maintain a low profile and keep their names out of the news media. But officers of the Palestinian Authority’s General Intelligence Service arrested one of them, Saleh Abu Mayala, on Friday night as he was walking from his car to his home in the West Bank city of Hebron, according to two Palestinian officials and the leader of the Palestinian business delegation to Bahrain, Ashraf Jabari.
The delegation had returned to the West Bank on Thursday. Palestinian officials have maintained official secrecy about the arrest and it was not clear on Saturday whether Mr. Mayala had been formally charged, but one Palestinian official called his attendance at the conference an illegal act of betrayal.
Intelligence officers summoned another conference participant, Ashraf Ghanem, also from Hebron, by phone on Friday night, after they did not find him at home. Instead of turning himself in, Mr. Ghanem was sheltering on Saturday in Mr. Jabari’s house, according to the two men, in the Israeli-controlled section of Hebron — an area where the Palestinian Authority security forces cannot operate without prior coordination with the Israelis.
A Palestinian security official, who spoke on condition of anonymity because he was not authorized to speak publicly on a sensitive security issue, said the Palestinian businessmen’s participation in the conference was “tantamount to betrayal,” adding that Palestinian law punishes those who betray their homeland. Once the Palestinian leadership had decided to boycott the event, he said, participation was not optional or a matter of individual freedom.
A second government official, also speaking on condition of anonymity, confirmed the arrest. He said there had been public pressure on the Authority to put those who attended the conference on trial.
Reached by phone, Nabil Abu Rudeineh, the Palestinian Authority’s minister of information, said he did not know anything about Mr. Abu Mayala’s arrest.
The Trump administration said the conference was meant to encourage investment of more than $50 billion to jump-start the Palestinian economy and aid neighboring Arab countries, helping to build a foundation for a future peace.
But the Palestinian leadership cut off diplomatic ties with the Trump administration after it recognized Jerusalem as Israel’s capital in late 2017 and moved the United States embassy from Tel Aviv to the contested holy city. The Palestinian establishment rejected the notion of putting economics before a political solution, fearing they could be seen as having sold out their national aspirations.
Prominent Palestinian business leaders stayed away from the Bahrain conference.
Mr. Jabari, the delegation head, who traveled to Bahrain publicly, was the only Palestinian speaker on the agenda. He said in a telephone interview Saturday that the delegation consisted of 13 Palestinians from the West Bank cities of Hebron, Bethlehem, Ramallah and Jenin and from East Jerusalem.
The Authority, he said, had “misunderstood” the purpose of the conference, which he described as about an economic vision for the period after a peace agreement is reached between the Israelis and the Palestinians. He said that no politics were discussed there, and insisted he had not broken any Palestinian law.
Mr. Jabari, the leader of a large clan in Hebron, is a controversial figure among Palestinians. He has forged ties with Jewish settlers and helped form a chamber of commerce in which Palestinian and settler businesses work together. Palestinian leaders have criticized Mr. Jabari as a political outcast who faces outstanding warrants for bad debts.