Remains of Palestinian leader Yasser Arafat are being exhumed to help determine the cause of his death.

Al Jazeera’s Nadeem Baba, reporting from the West Bank capital, Ramallah, said that “according to Tawfiq al-Tirawi, the head of the Palestinian committee investigating Arafat’s death, the process of exhumation started at midnight local time (22:00 GMT) on Monday”.

“We’re not getting this confirmed by other sources … this whole process has been surrounded by secrecy. What I can tell you is that some of my colleagues spotted members of the French team here in Ramallah to observe the exhumation and then be involved in those tests.”

Three teams of international investigators travelled on Monday to the muqataa, the Palestinian Authority (PA) headquarters, where Arafat is buried. They could be seen bringing equipment to the site throughout the day.

A nine-month investigation, the results of which were broadcast earlier this year, found elevated levels of polonium on Arafat’s final personal effects, raising new questions about what killed the longtime Palestinian leader.

French legal experts have also begun to gather evidence on the case in preparation for a possible trial, including testimony from people in the West Bank, according to Palestinian officials.

The teams are operating under a near-media blackout imposed by the PA, which had promised a transparent and open investigation.

None of the investigators contacted over the past few days were willing to speak on the record.

And late on Monday, the PA said it would not allow lawyers representing Arafat’s widow, Suha, to attend the exhumation, without offering any reason for its decision.

On Monday night, workers with hand tools drilled through more than four metres of concrete over Arafat’s body. Investigators have collected several samples on the way down to took at polonium levels.

The whole process will take about 10 hours, and Arafat will be reinterred in a military ceremony on Tuesday afternoon, according to Tirawi.

(Al Jazeera)