For 66 days, Palestinian prisoner Khader Adnan refused to eat.

Now - after a promise from Israel that he will be freed in April - Adnan has agreed to end his hunger strike.

Held without trial by Israel, the 33-year old member of the militant group Islamic Jihad has inspired mass protests by Palestinians. News of the deal sparks celebrations.

But it may be too late to save Adnan, says his lawyer Jawad Boulos.

(SOUNDBITE) (Arabic) JAWAD BOULOS, LAWYER REPRESENTING KHADER ADNAN, SAYING:

"Starting this evening Khader will stop his hunger strike, Khader will get the medical treatment that is needed, because I knew yesterday, from the doctor who is responsible in Safed hospital, his condition is very bad - he may face certain death."

Israel has not charged Adnan with any crime and has kept the reason for his arrest and detention secret.

As the release deal was announced, Israel's High Court cancelled an appeal hearing in Adnan's case, avoiding a high-profile examination of the controversial practice of detention without trial.

For decades, the court has backed the government's argument that detention without trial is necessary for security.

Katharine Jackson, Reuters.