The judges will visit Arafat's mausoleum in the West Bank city of Ramallah, the source said on condition of anonymity. Arafat died aged 75 in France in November 2004 and French doctors were unable to say what had killed him.
Many Palestinians are convinced he was poisoned by Israel.
French prosecutors opened a murder inquiry in August after Al-Jazeera television broadcast an investigation in which Swiss experts said they had found high levels of radioactive polonium on Arafat's personal effects.
The French probe followed a request by Arafat's widow Suha, but it has caused a split within the family, with the veteran leader's nephew Nasser al-Qidwa condemning plans to exhume the body for tests as "a hateful idea."
Polonium is a highly toxic substance rarely found outside military and scientific circles. It was used to kill former Russian spy turned Kremlin critic Alexander Litvinenko, who died in 2006 after drinking tea laced with the poison at a London hotel.