Private jet owned by Florida property tycoon has twice flown Palestinian men from Arizona to Tel Aviv.

A private aircraft owned by a businessman close to US President Donald Trump was reportedly used to transport Palestinian detainees to the Israeli-occupied territories.

According to The Guardian, the aircraft-owned by Florida property developer Gil Dezer-was chartered as part of a secretive deportation effort run by US Immigration and Customs Enforcement (ICE).

Public records cited in the report show that the Dezer family has longstanding business ties with Trump and has donated significant sums to his political campaigns.

The jet has twice flown Palestinians from Arizona to Tel Aviv. Each time, the flights carried Palestinian men detained by ICE from a deportation facility in Phoenix to Tel Aviv, where they were later transferred by armed Israeli forces and released at a military checkpoint in the occupied West Bank.

Each flight is estimated to cost between $400,000 and $500,000.

Witness accounts described detainees arriving disoriented, wearing prison-issued clothing, and carrying their belongings in plastic bags.

"They were not wearing jackets or coats, and the weather was very cold and windy that day," said a local resident who helped the men.

"They stayed at my place for two hours, during which I fed them, and they called their families, who either came to pick them up or arranged transportation for them."

Some had not been allowed to contact their families for many months and were believed to be missing, the report said.

Israeli newspaper Haaretz reported that the deportations followed "an unusual request from Washington to Israel," and were conducted with the approval of Israel`s internal security agency, Shin Bet.

Some of the Palestinian men hold green cards, allowing legal residency in the United States, while several have wives, children, and other close family members in the country. Some had been detained by ICE for weeks, and at least one was held for more than a year, the report added.

The report has sparked outrage among rights advocates, who say ICE is enforcing immigration policy through secretive arrangements that separate families, evade scrutiny, and hand sensitive government functions to politically connected private interests.

Several immigration attorneys also told The Guardian that deporting Palestinians to Israel could breach international law.

According to Gissou Nia, director of the Strategic Litigation Project at the Atlantic Council, the principle of non-refoulement prohibits forcibly returning individuals to a place where there are substantial grounds to believe they could face irreparable harm, including persecution, torture, ill-treatment or other serious human rights violations.

"The United States is bound by international treaties that explicitly prohibit this, including the Convention against Torture," she added.

Human rights groups and UN officials have documented abuse of Palestinian detainees in Israeli custody. The Office of the UN High Commissioner for Human Rights has reported cases of arbitrary detention, prolonged incommunicado holding, and accounts from released prisoners describing torture and severe mistreatment.

Human Rights Watch has likewise said Palestinian detainees have faced degrading treatment and other forms of abuse that could amount to serious violations of international law.