WASHINGTON – The family of an Israeli citizen last seen entering Gaza more than three years ago appealed to US lawmakers last week for help in securing his release.Avera Mengistu’s family met with White House officials and members of Congress hoping the weight of the United States could somehow pressure Hamas to let him go. The Gaza-based terrorist organization has released propaganda suggesting they are holding Mengistu, but has not offered proof of his life for years.Ilan Mengistu, Avera’s brother, told The Jerusalem Post in an interview on Thursday that the family is working with nongovernmental organizations along with US and Israeli officials in their search for information and, hopefully, his freedom.“When I first heard what Avera had done, I was mad at him – I was blaming him,” his brother said. “But, as time goes by, I know that a personal in an emotional crisis is not necessarily aware of the dangers he is walking into and that his judgment is compromised.”Avera, 31, was admitted by his family to a hospital for mental illness just months before he wandered into Gaza in September 2014. It was the untimely death of his brother from sickness that destabilized Avera originally, his family says.“ We know that he walked into Gaza alive ,” Ilan continued.“ There is documentation from the IDF. And we know that in the first few months he was held by Hamas. “ The Mengistu family met with Congressmen Ted Deutch (D-Florida), Brad Sherman (D-California) and Ed Royce (R-California) on Capitol Hill last week, as well as US President Donald Trump’s special representative for international negotiations, Jason Greenblatt, at the White House.Ilan said that Greenblatt encouraged the family to bring together members of Congress from both sides of the aisle to apply maximum pressure on Hamas to release Avera.“We trust him that he’ll do whatever is possible,” Ilan said. “He recommended that we meet with some members of Congress, and together they could convene bipartisan members of Congress to push for Avera’s release. ” They described Greenblatt as “deeply moved” by Avera’s story. The special envoy posted a message on Twitter about their meeting, including photos of Avera with graphics calling for his freedom.“Avera has been held by Hamas in Gaza for over 1,000 days since he disappeared in September, 2014,” Greenblatt wrote. “It is outrageous that Hamas will not let him return home or communicate with his family.”A source close to Greenblatt said he, indeed, is deeply saddened by Avera’s plight, and confirmed that the special envoy was doing “everything he could to help.”“It’s so tragic, and just so sad – unfortunately, given that it is Hamas seemingly holding him, this reflects their disregard for humanity,” the source said.Another suspected captive of Hamas, Hisham al-Sayed, is also said to suffer from a psychological condition. No proof of life for al-Sayed has been offered, either."Hamas has been portraying him numerous times as a soldier, which is false – they’re just taking a photo of someone else and photoshopping him on it or showing someone else. He was never a soldier,” Ilan said, noting that Palestinian Authority leadership had also perpetuated this false narrative around his brother.“I really don’t know what they want. I know that, currently, they’re holding him in a cruel and unusual way against every international treaty and convention. So we can’t really know for sure ,” Ilan added. “ He’s an innocent, private citizen that has nothing to do with the conflict."