Tawfiq al-Tirawi said the medical committee led by Abdullah al-Basheer is researching Arafat's death in conjunction with international specialists and will brief officials on the results once the probe is in its final stages, Palestinian news agency Ma'an reported Monday.
"We haven't initiated the investigation based on the hypothesis that Arafat was killed by poison, but we agreed to begin an investigation searching directly for the killer regardless of the medical reports which will eventually show the method of killing and name of the toxin," al-Tirawi told Ma'an. "We are looking for a needle in the ocean," he added.
The Palestinian Authority said it was willing to exhume Arafat's body if necessary, al-Tirawi said.
Arafat, who died in November 2004, was a Palestinian leader, militant, and the 1994 Nobel Peace Prize laureate. He led the Palestine Liberation Organization, was president of the Palestinian National Authority and leader of the Fatah political party, which he founded in 1959.
Numerous theories have emerged about the cause of Arafat's death, including a platelet disorder, AIDS, liver disease and poisoning.