Investigators who exhumed the body of former Palestinian leader Yasser Arafat on Tuesday will be testing samples of tissue, possibly bone, and hair, a forensic specialist says. But they’ll be up against the clock in trying to detect the radioactive substance, polonium, that many Palestinians suspect may have been used to poison him.

It’s tricky looking for evidence of poisoning after a body has been buried, says Bruce Goldberger, director of forensic toxicology at the University of Florida, Gainesville.

“The investigators are likely taking small samples from various regions of the body for polonium testing,” Goldberger told NBC News. “Very small pieces of tissue are needed. You don’t need the whole body.” 

Investigators sampled Arafat’s remains without fully removing his body from the grave in the West Bank city Ramallah, Palestinian officials said. The Palestinian medical team gave samples to Swiss, French and Russian experts who will examine them in their home countries.

They’ll also need to test the soil. Arafat was buried according to Muslim tradition – wrapped in a cloth and placed directly into the ground. “They are going to certainly sample the soil immediately proximate to the body as well as further away from the body,” Goldberger said.

“The evidence should be there,” said Dr. William Bass of the University of Tennessee at Knoxville, who founded the original “body farm,” known officially as the Anthropology Research Facility, where students study real, decomposing human bodies.

Any chemicals would be in the remaining bone, tissue, hair and nails, Bass told NBC News.

They will be looking first and foremost for polonium. Arafat, 75, died in a French military hospital near Paris on Nov. 11, 2004, after his already-poor health took a sudden turn for the worse during an Israeli military siege of his Ramallah headquarters.

Arafat’s wife, Suha, ruled out an autopsy but she later filed a lawsuit, which prompted a French investigation. French and Palestinian investigations found no evidence of poisoning or other foul play.

But then the Swiss-based Institute of Radiation Physics discovered traces of polonium-210, the same radioactive compound that killed former KGB officer Alexander Litvinenko in 2006, on samples of Arafat’s clothing.

French experts have said it will be difficult to detect polonium eight years after Arafat’s death. Polonium-210 has a very short half-life, meaning it decays very quickly. Eight years is about the outside limit.

If it’s a radioactive substance that caused Arafat’s death, it would be detectable even if the body is decomposed, Goldberg said. It wouldn’t be like looking for an illegal drug such as cocaine, which would require testing of blood, urine and organ tissue.

And after eight years, the body is certainly decomposed, even if the soil is dry. Palestinian officials are not giving morbid details.

"The state of the body was exactly what you would expect to find for someone who has been buried for eight years. There was nothing out of the ordinary," Health Minister Dr. Hani Abdeen told a news conference.

“The only thing you can do is dig it up and look at it," Bass said.

That means checking the entire grave, Goldberger said.

“No doubt they are going to collect samples from the sheet he was buried in,” he said. “They are going to collect his hair for sure. Hair samples provide a long-term measure of drug and chemical exposure.”

Hair, which can last for thousands of years, is a great way to check for poisoning, said Goldberger, who examined the remains of 2-year-old Caylee Anthony, who was killed in 2008. Caylee’s mother Casey was cleared of her murder  in 2011 in a highly publicized case. He found no evidence about how she died.

“Once the drug and/or chemical is integrated into the hair, it stays there forever,” Goldberger said. Napoleon’s hair was tested for arsenic -- investigators found it but said it was likely from hair ointment.

“I worked on hair from Jesse James many years ago,” Goldberger added. He did not find hoped-for traces of morphine, which would have confirmed legends about the outlaw’s purported addiction to the painkiller laudanum in the months before he was shot to death in 1882.

What’s clear is that the tests on Arafat’s body will take time to produce results.

"In order to do these analyses, to check, cross-check and double cross-check, it will take several months and I don't think we'll have anything tangible available before March or April next year," said Darcy Christen, spokesman for Lausanne University Hospital in Switzerland.

Reuters and The Associated Press contributed to this report

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