The Palestinian Prisoner’s Society released the information after head of the organization’s legal unit, Jawad Boulus, visited Palestinian detainees in Hadarim jail.
There, he met with prisoner representative Ammar Mardi, and prisoner Karim Younis, the longest-serving prisoner in Israeli jails.
Seen among many Palestinians as a symbol of resistance untainted by corruption and infighting, polls have consistently shown Barghouthi to be one of the most popular Palestinian political figures.
Barghouti was detained by Israeli forces in 2002, convicted on charges of murder, and given five life sentences.
The circumstances of his conviction have been internationally criticized. During trial, he refused to present a defense, maintaining that the trial was illegal.
In December 2014, Barghouti criticized the PLO following its submission of a UN resolution submitted to the Security Council on the grounds that the resolution neglected issues of settlement expansion, Jerusalem, prisoners, and the blockade on Gaza.
He argued that any talk of land swaps would weaken the Palestinian right to self-determination and a sovereign state on land occupied in 1967, noting that such a measure would be used to legalize settlement building.