Q&A: Exhumation of Yasser Arafat
The body of the Palestinian leader, Yasser Arafat, has been exhumed from a mausoleum in the West Bank so that experts can determine whether he was poisoned.
The exhumation follows a TV documentary which reported that traces of radioactive polonium-210 had been found on his personal belongings.
Arafat died on 11 November 2004, aged 75, after a month-long illness.
How did Arafat die?
In 2005, the New York Times obtained a copy of Arafat's medical records from two Israeli journalists, Avi Isacharoff and Amos Harel, who had been given them by a senior Palestinian official.
According to the records, Arafat's illness began four hours after he ate a meal on the evening of 12 October 2004 inside the Muqataa presidential compound in the West Bank city of Ramallah. Israeli forces had kept him isolated there for three years, accusing him of sponsoring a wave of deadly attacks by Palestinian militants.
For the next two weeks, he vomited, and had abdominal pain and diarrhoea, but did not have a fever. He became stuperous and lost 3kg (6.6lbs), according to the records. He was seen by a team of Palestinian, Egyptian, Jordanian and Tunisian doctors, and was treated for flu and thrombocytopenia, an abnormally low platelet count.
The records indicated that Arafat did not receive antibiotics until 27 October - 15 days after the onset of his illness. Two days later he was flown by helicopter to Jordan and then private jet to the Percy Military Training Hospital in Clamart, outside Paris.
It was only once Arafat arrived in Paris that he was diagnosed with a serious blood disorder - disseminated intravascular coagulation (DIC) - which the French doctors were never able to control and led to his death.
Arafat did improve for a time at Percy hospital, but he slipped into a coma on 3 November, when he was moved to intensive care. He had massive haemorrhagic stroke on 8 November and died three days later.
Why do people think he was poisoned?
Many senior Palestinian officials claim that Arafat was poisoned by Israel.
Israel's prime minister at the time of Arafat's death, Ariel Sharon, saw the Palestinian leader as a terrorist and an obstacle to peace.
In 2002, Mr Sharon told the Maariv newspaper that he regretted not "eliminating" Arafat during the invasion of Lebanon in 1982. But he also stressed that Israel had later made a "commitment" not to harm him.
However, Mr Sharon is alleged to have told former US President George W Bush in April 2004 that he no longer felt bound by his promise.
Israel has strenuously denied that it had anything to do with Arafat's death.
An Israeli government official told the BBC on 27 November 2012: "The Palestinians repeatedly raise conspiracy theories regarding his death."
"We have always said that they hold all the information and that there is no room for these theories, their allegations are untrue," he added. "All the medical files are in the hands of the family or the Palestinian Authority, but for some reason they have not released them to this day."
What do his medical records say?
Despite extensive testing, the French doctors never discovered the specific cause of the infection that led to the DIC, according to the medical records obtained by the New York Times.
Biopsies performed did not show evidence of any infectious agent or cancer, the records state. Tests carried out by a laboratory in Tunis on cultures of blood, stool, urine and bone marrow were also negative.
Specimens were sent to three laboratories for standard toxicology tests to detect metals and drugs, but none were found.
No post-mortem was performed because his widow, Suha, objected to one.
Independent Israeli and American experts who reviewed Arafat's records told the New York Times that it was highly unlikely that he was poisoned. They said he did not suffer the extensive kidney and liver damage they would expect from a poison, although he did have jaundice.
They also said the course of his illness and pattern of his symptoms also made rumours that he died of Aids improbable. The records make no mention of an Aids test being carried out, which surprised some medics.
What prompted the exhumation?
On 3 July 2012, an al-Jazeera documentary reported the results of a nine-month investigation that tried to discover what killed Arafat.
It reported that scientists at the Institute of Radiation Physics (IRA) at the University of Lausanne in Switzerland had found "significant" traces of a highly radioactive and toxic material on personal effects given to his widow after his death, including his trademark keffiyeh.
Francois Bochud, the director of the institute, said its tests had found an "unexplained, elevated amount of unsupported polonium-210 in the belongings of Mr Arafat that contained stains of biological fluids".
In some cases, the elevated levels were reportedly 10 times higher than those on control subjects, and most of the polonium could not have come from natural sources.
To confirm the theory that Arafat was poisoned by polonium-210 it would be necessary to exhume and analyse his remains, Dr Bochud added.
Arafat's widow subsequently confirmed that she would submit a request to the Palestinian Authority, telling al-Jazeera: "We have to go further and exhume Yasser Arafat's body to reveal the truth."
Mrs Arafat also filed a civil suit at a court in the Paris suburb of Nanterre, alleging that her husband was murdered by an unnamed "perpetrator X". French prosecutors began a murder inquiry in August.
The Palestinian Authority welcomed the decision and granted French investigators and the Swiss scientists permission to exhume Arafat and take samples for testing. Russia was also asked to send experts.
What is polonium-210?
It is a naturally occurring radioactive material that emits highly hazardous alpha (positively-charged) particles. The substance, historically called radium F, was first discovered by Marie Curie in the 19th Century.
There are very small amounts of polonium-210 in the soil and in the atmosphere, and everyone has a small amount of it in their body. But at high doses, it damages tissues and organs.
It cannot pass through the skin, and must be ingested or inhaled.
Although polonium-210 occurs naturally, acquiring enough of it to kill someone would require individuals with expertise and connections. They would need sophisticated lab facilities - and access to a nuclear reactor. Alternatively, it could be obtained from a commercial supplier.
The former Russian spy Alexander Litvinenko died of exposure to polonium-210 in London in 2006. The UK authorities have accused Andrei Lugovoi, an ex-KGB officer, of poisoning his tea.
Despite the reported discovery of elevated levels of polonium-210 on Arafat's personal effects, the medical profession is generally sceptical about claims that he was poisoned with it.
Darcy Christen, a spokesman for the Institute of Radiation Physics (IRA), which carried out the tests for al-Jazeera, even told Reuters news agency in July that the clinical symptoms described in Arafat's medical records were not consistent with polonium-210 poisoning.
Eight years is also considered the limit to detect traces of polonium, which has a half-life of 138 days, meaning the radioactivity of a sample drops by half during that period. Arafat's death was just over eight years ago.