FORT WORTH, Texas -- Lawyers for Ethan Couch said Tuesday the 18-year-old was dropping his fight against being sent home to Texas from Mexico.

Authorities allege that Couch and his mother fled to Mexico in December as prosecutors in Texas looked into whether he violated his probation stemming from a drunken-driving accident that killed four people.

The two were caught last month in Mexico, and Couch's mother was quickly deported. But the 18-year-old won a delay, based on a constitutional appeal that normally leads to a lengthy trial process.

Today, his lawyer in Texas said documents have been filed to lift the objections to Couch's return to the United States, but he didn't say how long the process would take. Officials in Mexico say they haven't seen anything indicating that Couch has agreed to drop his deportation fight.

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Earlier Tuesday, Brown said he was investigating whether the 18-year-old fled to Mexico or was taken against his will.

After a hearing in the case in Fort Worth, Brown said the question of whether his client "was voluntarily or involuntarily taken to Mexico is something that is still being investigated."

Lawyers for Couch's mother, who is charged with hindering the apprehension of a felon, did not comment on the allegation.

Tuesday's juvenile court hearing was scheduled to determine whether Couch, who is being held in Mexico, violated his probation and if the case should be transferred to adult court. But the judge delayed the hearing shortly after it started, after Couch's attorneys said his parents weren't properly notified. The hearing was rescheduled for Feb. 19.

The drunken-driving case drew widespread derision after an expert called by Couch's lawyers argued he had been coddled into a sense of irresponsibility by his wealthy parents, a condition the expert called "affluenza."

Couch was 16 at the time and driving at three times the legal intoxication limit for adult drivers. Investigators said he rammed his pickup truck into a crowd of people trying to help a stranded motorist. The wreck killed four people and injured several others.

A juvenile court judge gave the teen 10 years' probation, outraging prosecutors who had called for him to face detention time.

Authorities apprehended Couch and his mother, Tonya Couch, last month in Puerto Vallarta, Mexico. Tonya Couch was quickly deported and has been released on bond in Texas. The 48-year-old is charged with hindering the apprehension of a felon.

Ethan Couch remains in a Mexico City detention facility.

Tonya Couch, 48, mother of "affluenza teen" Ethan Couch, 18, in image provided to Mexican authorities by U.S. law enforcement officials Attorney General's office in Mexican state of Jalisco

Law enforcement officials say Tonya and Ethan fled to Mexico after a video surfaced that appeared to show the teen at a party drinking alcohol. If he was drinking, it would violate his probation and could lead to jail time.

Law enforcement officials believe the mother and son had a going away party shortly before driving across the border in her pickup truck, making their way to Puerto Vallarta. They were first tracked to a resort condominium after ordering pizza. They had moved on by the time authorities arrived, but a witness directed police to an apartment in Puerto Vallarta's old town.

When they were arrested, authorities said Ethan Couch appeared to have tried to disguise himself by dying his blond hair black and his beard brown.

According to the arrest warrant affidavit, Ethan Couch was "scared" after the video surfaced and did not respond to a Dec. 3 call from his probation officer to report for a drug test. He also did not appear for a scheduled meeting with the officer on Dec. 10.

A search warrant of bank and phone records found Tonya Couch had withdrawn $30,000 from a personal account and there was no other activity after Dec. 3. That day she also called her husband Fred Couch to say he would never see them again.

Authorities have previously said they had no evidence Fred Couch was involved in helping Tonya and Ethan Couch flee.