Israel 'prime suspect' behind Yasser Arafat's death, chief Palestinian investigator says In the first authoritative response from the Palestinian Authority [PA] to a Swiss report suggesting that Arafat suffered radioactive polonium poisoning before his death in 2004, Tawfik Tirawi said it was clear that he did not die of old age, chronic illness or from natural causes. "The basis [of the investigation] is to find who stands behind the assassination of Yasser Arafat and who had the technical and scientific resources for that," Mr Tirawi, head of an official inquiry team, told a news conference in the West Bank city of Ramallah. We say that Israel is the prime and only suspect to be accused and we will continue to have a complete investigation of the to find out all the details and factors of the case. Mr Tirawi blamed Israel a day after several official Israeli officials stated publicly on Thursday that the government of former prime minister Ariel Sharon - who was in office when Arafat died - was not responsible. While many Palestinians have long pointed the finger at Israel, there has also been speculation that the late leader may have been poisoned by a member of his own inner circle before he suddenly fell ill in October 2004. The scientists said the former PA president must have been poisoned deliberately but said there was not enough evidence to conclude that it caused his death. The Swiss report was handed to PA officials this week. However, a separate report compiled by Russian scientists and also given to the PA in recent days concluded there was insufficient information to say Arafat sustained polonium poisoning, Dr Abdullah al-Bashir, a Jordanian physician and a member of the Palestinian inquiry team told reporters. Al-Jazeera, the Qatar-based satellite news network that first aired the Swiss findings, broadcast an interview with an anonymous source who said Russia's foreign ministry had pressured the Russian scientists to reach conclusions that would not offend Israel. The Russian scientists were allowed to examine only four out of 20 samples, which yielded "suspiciously low" levels of polonium-210, he said.