The sealed tomb of former Palestinian leader Yasser Arafat was penetrated Tuesday morning as investigators took samples from his remains in an attempt -- eight years after his death -- to determine whether he was poisoned.

Arafat died in November 2004 at a French military hospital following months of illness. The immediate cause of death was a massive stroke, but the underlying reasons were unclear, leading to widespread belief in the Arab world that the 75-year-old was poisoned -- a claim his family has also long-alleged.

The exhumation -- which began before dawn under the cover of huge sheets of blue tarpaulin -- took place at Arafat's former compound in the West Bank city of Ramallah.

It was prompted after Swiss investigators found recently high concentrations of polonium-210 on articles of clothing provided by Arafat's widow, causing Palestinian officials to launch a renewed probe into his death. After the Swiss investigators said their tests were inconclusive, they noted new samples needed to be directly from Arafat's remains in order to gain a clearer understanding of what caused his death.

Reporting from Ramallah Tuesday, CTV's Janis Mackey Frayer said the original plan was to exhume the body, then move the remains to a nearby mosque where the samples could be taken. However, technical difficulties caused officials to decide to leave the remains in the tomb, and instead take samples on-site.

"Bear in mind, this is all happening away from prying eyes or any television cameras. This has been done completely in secret," Mackey Frayer told CTV's Canada AM. "The Palestinian committee that is heading this investigation said they wanted to do their utmost to preserve the dignity of the late Palestinian leader and they didn't want to turn it into too big of a show."

By mid-morning, the grave was reclosed.

Swiss, Russian and French experts were present during the exhumation. They will each examine the samples in their own countries.

Earlier, samples were taken from Arafat's bedroom, office and personal belongings.

The Institute of Radiation Physics in Switzerland discovered this summer elevated traces of polonium-210, the same substance that killed Alexander Litvinenko, a former KGB officer turned Kremlin critic, in 2006.

Arafat's widow Suha had originally declined to have an autopsy performed on the late leader, and only changed her mind after the traces of polonium-210 were found, Mackey Frayer said.

"It was only earlier this year she agreed to turn over these belongings and, upon learning of the polonium, she urged French authorities to open a murder inquiry, which they did ... and which resulted in Palestinian authorities putting together an investigation committee and leading to the exhumation we saw today."

It is expected to take months before any results are available from the testing. And after eight years, it's a long shot that polonium-210 would be detectable in any case.

Within the Arab world there has long been a suspicion that Israel played a role in the death of the Palestinian leader, who was a staunch symbol of nationalism. Israel has always denied any involvement in the 75-year-old's death.

Suspicions about Arafat's death were rekindled this summer when Al-Jazeera, the Arab news network, took some of Arafat's belongings to the Swiss lab for testing. The belongings included a fur hat and woolen cap with some of his hair, as well as a toothbrush and some clothing with urine and blood stains. The articles were provided by Arafat's widow.

Public reaction in the West Bank was mixed Tuesday.

Nidaa Younes, a Palestinian government employee, said it was unnecessary to exhume the remains. "Our religion forbids exhuming graves. It is not nice at all to do this, even if religion permits it in some cases," she said, adding that she believes Israel was responsible for Arafat's death.

Ramallah resident Tony Abdo said he supports the exhumation, expecting it to prove that Arafat did not die a natural death.