(Reuters) - A Swiss laboratory will help investigate the unexplained 2004 death of Palestinian leader Yasser Arafat only if it receives guarantees its findings will not be used for political purposes, a spokesman for the lab said on Wednesday.

A committee looking into the Palestinian president´s death has asked the Swiss Radiophysics Institute, which found traces of a deadly polonium isotope on Arafat´s clothing provided by his widow for a recent Al Jazeera television documentary, to examine his remains.

"We have been invited by the Palestinian National Authority and we are currently studying the most appropriate way of responding to this request," Darcy Christen, spokesman for the institute, said in an emailed reply to a Reuters question.

"Meanwhile, our main concern is to guarantee the independence, the credibility and the transparency of any involvement that we may have," Christen said.

Arafat was a guerilla-turned-statesman who came to symbolize the Palestinian quest for statehood throughout decades of war and peace with Israel.

After being stricken with an ailment which remains unknown, the president was airlifted to France in 2004 when he fell ill during an extended siege Israel mounted on his compound during a Palestinian uprising. He died shortly thereafter.

His death aroused rumors among Palestinians of an assassination, which many blamed on Israel. An investigation into the case could rekindle Palestinian hostility toward Israel and widespread suspicions that a local collaborator may have poisoned him under directions from the Jewish state.

Tawfiq Tirawi, head of the committee looking into the death, told reporters the Swiss institute was seeking assurances before sending experts to the Palestinians´ administrative capital in Ramallah, but did not disclose the nature of those guarantees.

"The content of our correspondence pertained to the necessity of their arrival and our welcoming of their presence in Palestine as quickly as possible, but they have some legal issues and legal procedures," Tirawi said.

Exhuming Arafat´s body from its limestone mausoleum in the center of the Palestinian Authority´s presidential compound in Ramallah would be a deeply emotional move for Palestinians, but one for which the local investigative committee says the government and his family are prepared.

"We´ve asked for (the Swiss team´s) arrival at full speed...the leadership has resolved to grant them any investigations they might request," Tirawi said.

After the Arafat documentary was aired, his widow Suha petitioned a French court to open a murder probe, claiming the circumstances of his death had been mysterious and French forensic authorities had disposed of samples taken from his body with undue haste.

Palestinian officials have called for an international investigation into the case, along the lines of the United Nations Special Tribunal for slain Lebanese Prime Minister Rafik al-Hariri, and the Arab League has formed a special committee to advocate for a United Nations inquiry.

(Additional reporting by Tom Miles in Geneva and Ali Sawafta in Ramallah; Editing by Michael Roddy) (© Thomson Reuters 2012. 08/08/12)