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.

Immigration officials transported 238 Venezuelan men from the United States to a notorious maximum security prison in El Salvador over the weekend, despite a court order from a federal judge prohibiting the government from carrying out the expulsions.

Human rights advocates warn that the deportees legal rights were violated as they were transferred to the CECOT, a mega-prison established by El Salvador’s President Nayib Bukele for his crackdown on gangs in the country. The facility, according to the Associated Press, can hold up to 40,000 inmates; up to 70 people are housed in a single cell.