Yasser Rajoub, 58, was detained on Jan. 17 and sentenced to six months administrative detention without charge or trial.
He was released after four months because he has advanced lung cancer, ministry spokesman Riyadh Al-Ashqar said.
Lawyer Tariq Barghouth, who works for the Palestinian Authority’s Ministry of Prisoners Affairs, said Wednesday that the prosecutor agreed to release Rajoub after his condition worsened.
Rajoub, from Hebron in the southern West Bank, had spent over 14 years in Israeli detention. The Hamas leader heads the Dura society for orphans.
He was among hundreds of Hamas leaders deported to Lebanon by Israeli Prime Minister Yitzhak Rabin in the 1990s.
Rajoub's family hope to send him for treatment abroad, his lawyer said.
