John Simpson: Yasser Arafat death 'was always suspicious'
7 November 2013 Last updated at 22:45 GMT
Swiss scientists have confirmed that the late Palestinian leader Yasser Arafat had high levels of radioactive polonium in his body when he died, according to tests.
However, they could not say whether polonium poisoning had caused his death in 2004.
The BBC's World Affairs Editor John Simpson has been examining the findings and said that there always seemed "something highly suspicious" about Mr Arafat's death.