UNDATED (CBS) -- Forensic teams in the West Bank city of Ramallah have exhumed the body of Yasser Arafat. They're trying to determine if someone killed the longtime Palestinian leader.

Palestinian leaders laid wreaths outside the West Bank grave of Yasser Arafat after forensic experts exhumed his body.

International investigators took samples from his remains to determine if someone poisoned him.

Arafat died eight years ago at a hospital in France after an unexplained illness. Some Palestinians, including Arafat's widow, have blamed Israel for his death. Israel has repeatedly denied the allegation.

A murder investigation began last summer after a Swiss lab found high levels of a deadly radioactive substance, Polonium 210, on Arafat's clothing. Scientists said they needed to examine his remains to know more.

Big blue tarps around Arafat's grave kept prying eyes away as workers drilled through layers of concrete to reach the tomb.

Some of Arafat's supporters were opposed to disturbing his gravesite. Others feel it was necessary to find the truth. One man says, "We have to know why he died because he represents the Palestinian people and the Arab world."

Experts from Switzerland, France and Russia will test the samples. It could take months for the results to come back, and even then the mystery may not be solved. Polonium decomposes quickly. If Arafat was murdered, experts say they may never know.

Officials had planned to re-bury Arafat in a larger ceremony with military honors. But that was called off after authorities were able to take the samples without removing his body.