naturally on Arafat's personal belongings. On 12 October 2013, the British medical journal The Lancet published a peer-reviewed article by the Swiss experts about the analysis of the 38 samples of Arafat's clothes and belongings and 37 reference samples which were known to be polonium-free, suggesting that Arafat could have died of polonium poisoning. On 27 November 2012, three teams of international investigators, a French, a Swiss, and a Russian team, collected samples from Arafat's body and the surrounding soil in the mausoleum in Ramallah, to carry out an investigation independently from each other. On 6 November 2013, Al Jazeera reported that the Swiss forensic team had found levels of polonium in Arafat's ribs and pelvis 18 to 36 times the average. According to the Swiss expert team (including notably experts in radio-chemistry, radio-physics and legal medicine), on a probability scale ranging from one to six, death by polonium poisoning is around five. While Al Jazeera reported that the scientist were "confident up to an 83 percent level" that polonium poisoning occurred, but Francois Bochud (the head of the Swiss team) clarified to Al Jazeera that this is not the case and that the scale does not allow a simple division like this; he stated only that the poisoning hypothesis by polonium is "reasonably supported". Forensic Biologist Nathan Lents of the John Jay College of Criminal Justice, said the report's results are consistent with a possible polonium poisoning, but "There's certainly not a smoking gun here." Derek Hill, a professor in radiological science at University College London who was not involved in the investigation, said "I would say it's clearly not overwhelming proof, and there is a risk of contamination (of the samples), but it is a pretty strong signal. ... It seems likely what they're doing is putting a very cautious interpretation of strong data." On 26 December 2013, a team of Russian scientists released a report saying they had found no trace of radioactive poisoning—a finding that came after the French report found traces of the radioactive isotope polonium. Vladimir Uiba, the head of the Federal Medical and Biological Agency, said that Arafat died of natural causes and the agency had no plans to conduct further tests. Unlike the Swiss report, the French and Russian reports were not made public, at the time. The Swiss experts read the French and Russian reports and argued that the radiologic data