Ilan Mengistu issued a statement Thursday following the publication that his older brother Avraham Mengistu had been abducted and is being held by Hamas in Gaza.
"This is a very difficult humanitarian case, because my brother is not in good health," Mengistu said, surrounded by tearful family members.
"On behalf of myself and my family, I request that the Israeli government do everything bring my brother home safely."
Mengistu also turned to the international community to intervene in the case and put pressure on Hamas to return Avraham.
He even pleaded directly to Hamas to free his brother, who has been missing and believed to be in Hamas captivity for ten months.
"My family and I decided to exercise restraint and we ask the Israeli public to exercise restraint. We will notify the public about any updates in the coming days."
Avraham Mengistu, 26, an Israeli citizen of Ethiopian origin, attempted to cross the border into Gaza in September and has been held there ever since, it was cleared for publication Thursday morning.
The Defense Ministry determined that Mengistu crossed the fence due to mental illness and that the move was not in any way a deliberate security risk.
Mengistu has a total of eight siblings; his father lives in central Israel and his mother lives in Ashkelon.
A second Israeli citizen, an Israeli Arab from the Bedouin village of Hura, is also being held by Hamas, the Defense Ministry said, without providing further details.
MK Avi Dichter (Likud), a former Shin Bet chief, told Army Radio on Thursday that it could be possible to combine indirect talks on the two captives with ongoing efforts to secure the return of body parts of two Israeli soldiers killed during Operation Protective Edge.
"If within the parameters of negotiations to get back the bodies of our soldiers...we can manage to get these two Israelis who are in Gaza it would be a great achievement," said Dichter.