French prosecutors have opened a murder inquiry into the death of the Palestinian leader Yasser Arafat in 2004. His family filed a case last month over claims that he was poisoned with polonium-210, a radioactive element. Swiss scientists hired by a documentary crew say they found traces of polonium on some of Arafat's belongings. The medical records of Arafat, who died at a military hospital near Paris in 2004, said he had a stroke resulting from a blood disorder. However, many Palestinians continue to believe that Israel poisoned him. Israel has denied any involvement.