Israel has barred a cousin of an assassinated Hamas operative from entering from Gaza for medical care, security officials said Tuesday, though the man's doctors warn his life is in danger.

Mohammed al-Mabhouh, 56, is the cousin of senior Hamas figure Mahmoud al-Mabhouh, who was assassinated in Dubai in January in a hit local authorities blamed on Israel's Mossad spy agency. Israel has not commented on the charge.

He was diagnosed with severe heart disease more than a year ago. He was permitted to travel from his home in the Gaza Strip to Israel for treatment several times, most recently last December.

Since then, Mohammed al-Mabhouh has been barred from Israel, though doctors say he needs open-heart surgery, a procedure Gaza's hospitals can't perform.

Israeli security officials say al-Mabhouh is banned from entering because of "suspicions of ties to terror activities of the person in question and his close family," an apparent reference to the assassinated Hamas figure.

Israel withdrew from Gaza in 2005 but continues to treat Gaza residents in its hospitals, subject to security clearance.

Physicians for Human Rights, a group that helps Palestinians, says it receives more than 1,000 requests a month for Gaza residents to go to Israel for treatment but receives permission for only about one quarter of them.

Al-Mabhouh said he has applied to enter Israel three times since February and missed six surgery appointments in the West Bank city of Nablus, where there are facilities for critical cardiac care. Gazans must travel through Israel to get to the West Bank and need Israeli security approval.

"At night, it feels like I'm choking and I can't breathe," said al-Mabhouh, who is confined to his bed much of the time, moving about only with the aid of a small scooter.

On Tuesday, Israeli lawmaker Dov Khenin demanded a more detailed explanation of the reasons for al-Mabhouh's rejection from Israel's Defense Ministry.

One remaining option is to try to shuttle al-Mabhouh through Gaza's border with Egypt, but the border is usually closed, and doctors say al-Mabhouh might not be not strong enough for the nine-hour trip to Cairo.