A federal judge has ordered the Trump administration to return a Maryland man who was mistakenly deported to a prison in El Salvador.

Kilmar Abergo Garcia, who was expelled last month along with hundreds of alleged gang members, must be returned to the US by no later than Monday, US District Judge Paula Xinis ordered.

US Immigration and Customs Enforcement (ICE) said in a recent court filing that deporting Mr Garcia was an “administrative error”. An immigration judge granted him a legal protection from deportation in 2019.

The White House has alleged Mr Garcia is an MS-13 gang member, but his lawyers argued there is no evidence to prove that he is gang-affiliated.

Mr Garcia’s lawyers also argued that that he has never been charged with a crime in any country.

Issuing her order on Monday, Judge Xinis called Mr Garcia’s deportation “an illegal act”.

“Congress said you can’t do it, and you did it anyway,” she told Justice Department lawyers.

US lawyers have argued that the government is powerless to reverse the deportation because Mr Garcia is now in Salvadoran custody.

Mr Garcia’s lawyers said the claims by the Trump administration were “outrageous”.

“They’re coming before this court and saying, ‘We’ve tried nothing and we’re all out of options,'” lawyer Simon Sandoval-Moshenberg told Judge Xinis.

Mr Garcia’s family, including his wife Jennifer Vasquez Sura – a US citizen – have been calling for his release since his deportation in mid-March. Ms Sura has told reporters that she has not spoken to her husband since he was taken by US authorities.

The case has outraged many who have raised concerns about recent deportations carried out by the Trump administration of noncitizens who are in the US lawfully.