Khader Adnan was greeted to a hero's welcome in his village near Jenin, in the northern West Bank, that included fireworks, songs and flags for Islamic Jihad, the militant movement to which Israel says he belongs.
Read: Al-Quds rally shows solidarity with Palestinians
Residents wore shirts donning Adnan's picture. The bespectacled 37-year-old, thin and with a long beard, was released before dawn in an apparent effort to limit attention to the move, initially expected at midday.
A spokeswoman for the Israeli Prison Authority confirmed the release but provided no other details.
Islamic Jihad congratulated Adnan in a statement for his "victory" and said a celebration was being organised in his village of Arraba for Sunday evening.
Adnan had been held for a year under administrative detention, which allows imprisonment without charge for renewable periods of six months indefinitely.
Of the 5,686 Palestinian prisoners currently held by Israel, 379 are detained under the procedure.
Read: Israel frees impounded Palestinian funds
His hunger strike, which had brought him near death by the time it concluded last month, had sparked warnings from the Palestinian government that it held Israel responsible for his fate. Regular protests were organised in support of him.
Adnan ended his hunger strike on June 28 after Israel agreed to release him, at which point he was transferred to an Israeli hospital.
An Israeli official said at the time that the deal was made possible after Adnan withdrew his demand that Israel undertake never again to place him under administrative detention.
The official said Adnan's deteriorating health and appeals from the International Committee of the Red Cross and the Palestinian Authority had contributed to the decision to release him.
Read: Israel returns 15 confiscated Gaza fishing boats
He was detained a year ago, shortly after the kidnapping and murder of three young Israelis, which triggered the arrests of hundreds of Palestinians in the occupied West Bank. The killings were part of an upsurge in violence in the run-up to the 2014 Gaza war.
Adnan had previously gone on hunger strike for 66 days in 2012 to protest against his detention. He was released at the end of the protest, during which he had ingested vitamins and salt. He refused to swallow anything except water during his most recent detention.
A long list of Palestinian prisoners have gone on hunger strike, including nearly 2,000 in 2012 to protest against the administrative detention policy.
The Israeli government in mid-June renewed efforts for legislation that would allow prisoners to be force-fed when their lives are in danger, sparking criticism from health experts and rights groups.
Read: Human Rights Watch asks UN to put Israel on child rights violators list
The bill was initially approved by the government in June 2014 at the height of another mass hunger strike of Palestinian prisoners during which 80 were hospitalised.
The Palestinian leadership submitted a report to the International Criminal Court last week that included the treatment of Palestinian prisoners in Israeli jails.
COMMENTS (4)
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ