The Texas teenager derided for his “affluenza” defence in a deadly drunken-driving case won a weeks-long in delay in extradition from Mexico, while his mother was in a Los Angeles jail on Thursday after being deported.

A court in Mexico granted fugitive 18-year-old Ethan Couch, who faces likely incarceration in Texas, a stay against deportation following his illegal entry into the country, a Mexican migration official said, speaking on condition of anonymity.

The stay could delay his return by weeks or months, the official said. The right to appeal against deportation filed by lawyers for the teen after his detention this week was accepted by the court, which will now review his case, the official added.

Ethan and his mother, Tonya Couch, 48, entered the country by land earlier this month, according to Mexican officials, though it was unclear where. The two were arrested on Monday in the Pacific Coast resort city of Puerto Vallarta.

The pair fled south after officials in Tarrant County, Texas, began an investigation into whether Couch violated the probation deal that kept him out of prison after he killed four people with his pickup lorry in 2013.

Tonya Couch, who was wanted on a charge of hindering apprehension, was flown out of Mexico to Los Angeles late on Wednesday. She is being held without bail in the Metropolitan Detention Center in Los Angeles and faces transfer to Texas, said Los Angeles police spokeswoman Jane Kim.

Officials have not announced a date for the move. But Tarrant County Sheriff Dee Anderson said Couch was not expected to be transferred until she is arraigned in California next week.

Couch is due in Los Angeles County Superior Court on Tuesday, Kim said.

A lawyer for Couch did not respond to a request to comment. If convicted of the hindering charge, she could face two to 10 years in prison, Anderson said.

Anderson said when Ethan Couch arrives back in the United States, he would appear at a detention hearing in the juvenile justice system. If found in violation of his probation, as seems likely, the judge could keep him in a juvenile facility or send him to an adult jail, he said.

At this point, he may only face a few months behind bars under the juvenile justice system. But Anderson said county prosecutors are looking at additional charges in the adult system.

Ethan Couch was transferred on Wednesday to a migration facility in Mexico City where illegal immigrants are held while their cases are processed. Most are from Central America.

“He’ll be there until his appeal is over, which will ultimately end in deportation,” the migration official said, adding that Couch would not be allowed out of the facility.

Inside the center, which lies in the sprawling working-class district of Iztapalapa in eastern Mexico City, Couch would sleep in a bunk bed in a dorm with likely three or four other people, and use communal washing facilities, the official said.

While there, Couch will only be allowed to receive visits from family members or legal representatives he has designated. He is not permitted access to cell phones or computers and must eat meals and go to bed at hours prescribed by the facility.

“All the foreigners are treated the same. He doesn’t have special conditions. He’ll live alongside all the foreigners there who are in the country illegally,” the official said.

During Couch’s trial in juvenile court over the crash in 2013, a psychologist testified on his behalf that he was afflicted with “affluenza,” meaning he was so spoiled by his wealth that he could not distinguish between right and wrong.

The diagnosis is not recognized by the American Psychiatric Association and was widely ridiculed.

Couch was convicted of four counts of intoxication manslaughter and sentenced to 10 years of drink- and drug-free probation, which critics saw as leniency because of his family’s wealth. His flight to Mexico rekindled anger over that sentence.

Couch and his mother absconded to Mexico after a video surfaced online apparently showing the teen at a party where beer was being consumed.

During their last days in Puerto Vallarta, the two lived in a modest apartment and tried to stay under the radar, local people and neighbours said.

(Additional reporting by Maurice Richter in Fort Worth; Writing by Jon Herskovitz; Editing by Kieran Murray and Tom Brown)

By Adam