French prosecutors on Tuesday opened a murder investigation into the 2004 death of former Palestinian leader Yasser Arafat. An investigating magistrate, yet to be named, will lead the French probe into possible premeditated murder, a legal source said.The probe comes after Arafat's widow Suha and daughter Zahwa launched legal action in France last month alleging the PLO leader was poisoned with radioactive polonium-210. A lawyer for Suha Arafat told Europe 1 radio that the French court was correct in recognizing its jurisdiction to investigate the case, since Arafat died in France."The tests done in Switzerland showed that Mr. Arafat, in all likelihood, died through poisoning," lawyer Marc Bonnant said. "This hypothesis must be proved, and if that's the case, then it's premeditated murder."Suha's allegation was based on a statement by the Institut de Radiophysique in Lausanne, Switzerland, which claimed it found an abnormally high level of polonium on Arafat’s belongings.The laboratory, whose initial findings were published as part of an Al Jazeera expose, has since confirmed that its researchers will test Arafat's body for the substance when the Palestinian Authority exhumes it from a mausoleum in Ramallah.Arafat was flown to France in October 2004 from his headquarters in the West Bank after his health deteriorated suddenly. He died a month later, at which time Arafat's aides quoted doctors as saying he had suffered a brain hemorrhage.However, allegations of foul play quickly surfaced, after the doctors who treated Arafat said they could not establish a precise cause of the illness that led to his death.Discussing the latest allegations, Dr. Ely Karmon, a specialist in chemical, biological, radiological and nuclear terrorism at the Interdisciplinary Center, Herzliya’s Institute for Counterterrorism, told The Jerusalem Post that the high levels of polonium reportedly found on Arafat's belongings in fact indicate that the toxin was planted on them long after his death.According to Karmon, the half-life of polonium makes it impossible for the substance to have been discovered at such high concentrations eight years later. "If it had been used for poisoning, minimal levels should be seen now. Yet much higher levels were found. Someone planted the polonium much later,” Karmon said.Nevertheless, Palestinian officials have called for an international investigation into the case, along the lines of the United Nations Special Tribunal for slain Lebanese prime minister Rafik Hariri.Foreign Ministry spokesman Yigal Palmor responded to France's inquiry by saying: "The complaint lodged by Suha Arafat with the French police does not address Israel or anyone in particular. If the French justice system has decided to open an investigation, we hope that it will shed light on this matter."Yaakov Lappin contributed to this report.