WASHINGTON, DC, United States (AFP) — A Venezuelan man who was deported to a notorious prison in El Salvador from the US took the first steps Thursday toward suing the Trump Administration over the ordeal.

Neiyerver Adrian Leon Rengel, 27, was one of 252 Venezuelan migrants sent to the Terrorism Confinement Center (CECOT) as part of US President Donald Trump’s high-profile mass deportation of migrants.

The Administration claimed that the men were linked to violent gangs, but they were sent without trial to El Salvador.

Now Rengel, who says he was beaten and abused during four months at CECOT, has filed an administrative claim with the Department of Homeland Security, the first step toward legal action against the federal government.

Rengel, who is claiming US$1.3 million in damages, was freed last week as part of a prisoner swap between Caracas and Washington. He is now living in Venezuela.

The filing on Rengel’s behalf was lodged by Democracy Defenders Fund (DDF) and the League of United Latin American Citizens.

“Federal government employees wrongfully and negligently detained and removed Mr Rengel from the country without cause or due process,” DDF said Thursday.

“Mr Rengel… was among the group of Venezuelan nationals who a federal court ordered the Government not to remove or to return if in transit — an order that was ignored.

”Instead, he was transferred to a notoriously brutal maximum security mega-prison in El Salvador, out of reach from anyone in the outside world, including his family.”

The Administration invoked the wartime Alien Enemies Act to carry out the summary deportations.

The New York Times reported that of the more than 250 men sent to El Salvador, it had found at least 32 had been charged or convicted with serious offences, but most of the men had no criminal connections.

Family members have insisted that the deported men were not gang members and that they were deported without due process.

“You don’t have to be a constitutional scholar for the Rengel case to set off alarms,” said Norm Eisen, executive chair of Democracy Defenders Fund.

“If you’re an American who believes in justice at all, this case should be shocking.

“Detaining and disappearing someone without cause or access to legal recourse is illegal and abhorrent.”