By Nelson Renteria
SAN SALVADOR (Reuters) -A law firm on Monday presented a habeas corpus lawsuit to El Salvador's Supreme Court in defense of 30 Venezuelan citizens jailed in the Central American nation's so-called mega-prison after being deported there by the United States.
The lawsuit, which will seek to question the legality of their detention, comes after the United States sent 238 Venezuelans to El Salvador, accusing them of being members of the Tren de Aragua gang.
The judges in charge of the case are allies of President Nayib Bukele, who has offered to hold U.S. prisoners in its prison system and accepted payment from the United States to do so.
Lawyer Jaime Ortega told reporters outside the court that while 30 Venezuelan nationals had granted them the powers of attorney to represent them, they would request habeas corpus for the rest of the Venezuelans detained in the country.
"We are demanding first that they be immediately released, and failing that, that there be an orderly and systematic transfer and repatriation as required by our immigration laws," he said.
Ortega said that his firm had been asked to represent the migrants by Venezuela's government and a committee of family members.
Some 137 of the group of Venezuelans were deported under an obscure U.S. wartime law targeting "alien enemies" that was quickly blocked by a U.S. judge, who ordered the flight carrying the Venezuelan citizens to turn around.
However, the Venezuelan citizens were later received in El Salvador where they were taken into custody in a massive anti-terrorism prison under a deal in which Washington is paying El Salvador's government $6 million, according to the White House.
Lawyers and family members of many of the migrants deny that they are members of Tren de Aragua and U.S. Judge James Boasberg ruled on Monday that they must be given the chance to challenge the government's claim that they are gang members.
The judge also cited accounts of poor prison conditions, including beatings, humiliations, irregular access to food and water and having to sleep standing up because of overcrowding.
El Salvador's presidential office did not respond to Reuters' request for comment regarding the prison conditions.
Located some 70 km (44 miles) from the capital San Salvador, the 23-hectare prison has been billed by local authorities as the largest in Latin America.
The court case come as the United States pursues a policy of mass deportations, including arrangements under which countries in Latin America agree to receive and organize the repatriation of foreign citizens.
(Reporting by Nelson Renteria; Writing by Sarah Morland and Raul Cortes; Editing by Brendan O'Boyle and Mark Porter)