Families of Venezuelan deportees held in El Salvador’s infamous Cecot prison can petition the Salvadoran government for their release – but the fruitfulness of that process is an open question in a country accused of arbitrary detention by rights groups and even the US State Department.

Invoking a 1798 law, the US president has sent hundreds of alleged gang members to high-security prison called 'black hole of human rights'

The arrival of the immigrants took place under agreement between the Trump Administration and El Salvador's President.