JERUSALEM - The West Bank tomb of Yasser Arafat has been screened from public view ahead of an expected exhumation, a Palestinian Authority official said Tuesday, four months after a television investigation raised new suspicions that the Palestinian leader had been poisoned.

The tomb lies within the walls of the compound in Ramallah where Arafat, long the symbol of the Palestinian national struggle, had been confined under an Israeli army siege for more than two years as the violence of the second Palestinian intifada, or uprising, raged outside.

The preparations for the exhumation have been enveloped in almost as much mystery and contention as was the death of Arafat in 2004 at age 75.

Arafat became ill in October 2004 and was flown out of his headquarters and transferred to a French military hospital, where he died about two weeks later.

Hospital records showed that he had died of a stroke that resulted from a bleeding disorder caused by an underlying infection. The infection was never identified. The hospital found no traces of poisons.

In July, Arafat's widow, Suha, called for an exhumation in an interview with Al-Jazeera, the Arabic television channel based in Qatar, after it reported that Yasser Arafat might have been poisoned with polonium, a radioactive element associated with KGB-style assassination intrigues.

At the University of Lausanne's Institute of Radiation Physics in Switzerland, doctors found what they said were unusually high levels of a highly toxic radioactive isotope, polonium 210, in certain items but added that further testing of Yasser Arafat's remains would be necessary before determining that he had been poisoned.

NEW YORK TIMES