Israel's health ministry said on Thursday the cause of a Palestinian prisoner's death remains unclear following tests on samples from his body, after Palestinian charges he was tortured in detention.
Two other Palestinian inmates, meanwhile, have suspended their hunger strike, an Israeli prisons official said.
The death last week of Arafat Jaradat, 30, triggered several days of clashes between Palestinian demonstrators and Israeli soldiers in the West Bank that left dozens of Palestinians wounded.
"It was found that the haemorrhages and fractured ribs found during the autopsy occurred close to death and are characteristic of the resuscitation attempts" by prison workers and medical staff, the health ministry said.
"No signs of other contusions were found. The toxicology tests were also negative," it said.
"There were no signs of significant change due to illness in other organs that could indicate cause of death; therefore, further tests to determine the cause will be performed."
On Sunday, the Palestinian minister of prisoner affairs, Issa Qaraqaa, citing the preliminary findings of an Israeli-Palestinian autopsy, reported bruises on Jaradat's body, muscle damage and broken ribs, saying that he died under torture.
Israel said at the time that the fractured ribs could have been caused by efforts to resuscitate him from an apparent heart attack.
The United Nations Special Rapporteur for human rights in the Palestinian territories, Richard Falk, called on Thursday for an independent investigation into the death.
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"The death of a prisoner during interrogation is always a cause for concern, but in this case, when Israel has shown a pattern and practice of prisoner abuse, the need for outside, credible investigation is more urgent than ever," he said.
"The best approach might be the creation of an international forensic team under the auspices of the UN Human Rights Council."
Israel's internal security minister, Yitzhak Aharonovitch, meanwhile, said on parliament's website that "all the documents will be transferred to the judge in charge of the case."
They will "perhaps be sent to an international organisation to eradicate the rumours which have been circulating," he said.
Also on Thursday, a prison official said two Palestinians held in Israeli custody without trial have ended their hunger strike but are still being treated in civilian hospitals.
Jaafar Ezzeddine and Tariq Qaadan had "started eating yesterday (Wednesday)," Israel Prisons Service spokeswoman Sivan Weizman told AFP.
Two other prisoners "Samer Issawi and Ayman Sharawna are both continuing their hunger strike," she said, adding they were now the only inmates still refusing food.
All four, who stopped eating several months ago but have been taking fluids and vitamins, are currently in hospital, she said.
A Palestinian prisoner support group said that Ezzedine and Qaadan would decide whether to renew their protest action after a hearing on their cases next week.
Under what Israel calls "administrative detention", suspects can be imprisoned without trial by order of a military court. Such orders can be renewed indefinitely for up to six months at a time.