The chairman of the medical commission of Palestinian inquiry commission into the death of late Palestinian leader Yasser Arafat, Abdullah al-Basheer holds a press conference with other Palestinian officials in West Bank City of Ramallah on July 12, 2012. Abdullah al-Basheer said on Thursday that the death of Yasser Arafat was the result of an unknown poison. (Xinhua/Chen Xu)

The chairman of the medical commission of Palestinian inquiry commission into the death of late Palestinian leader Yasser Arafat, Abdullah al-Basheer (C) holds a press conference with other Palestinian officials in West Bank City of Ramallah on July 12, 2012. Abdullah al-Basheer said on Thursday that the death of Yasser Arafat was the result of an unknown poison. (Xinhua/Chen Xu)

RAMALLAH, July 12 (Xinhua) -- The death of former Palestinian leader Yasser Arafat was the result of an unknown poison, a Jordanian doctor who started an inquiry in the incident said Thursday.