JERUSALEM — The West Bank tomb of Yasir Arafat has been cordoned off and 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 preparatory work, involving the removal of layers of stone and concrete, is being done manually and is expected to take at least two weeks.

“It needs to be done meticulously and privately, out of respect for the late president and our religious traditions,” the official said, speaking on the condition of anonymity because she was not authorized to speak about the issue....