Hundreds of Venezuelans who were deported to El Salvador from the United States in recent days could face long or indefinite detention in a prison system rife with human rights abuses, according to attorneys and experts on the region. 

Their families and lawyers fear there will be no recourse for them to return to the United States for scheduled immigration hearings or even return to their native Venezuela — all while those who spoke to NBC News continue to insist their loved ones and…