The U.S. Department of Justice has been quietly investigating a Tennessee traffic stop in 2022 involving Kilmar Abrego Garcia, the Salvadoran man at the center of a high-profile court battle over his mistaken deportation from Maryland to El Salvador by the Trump administration, ABC News has learned.

Federal investigators involved in the inquiry recently spoke with a convicted felon in an Alabama prison and questioned him about potential connections to Abrego Garcia, according to sources familiar with the investigation.

The inmate, Jose Ramon Hernandez-Reyes, 38, was the registered owner of a vehicle driven by Abrego Garcia when he was stopped by the Tennessee Highway Patrol in late 2022, according to the sources. Abrego Garcia was pulled over for speeding in a vehicle with eight passengers and told police they’d been working construction in Missouri.

Federal agents investigating the Tennessee incident appeared late last month at the Federal Correctional Institution in Talladega, Alabama, to question Hernandez-Reyes, who had an attorney present and was granted limited immunity, sources familiar with the interview said.

Hernandez-Reyes told investigators that he previously operated a “taxi service” based in Baltimore. He claimed to have met Abrego Garcia around 2015 and claimed to have hired him on multiple occasions to transport undocumented migrants from Texas to various locations in the United States, the sources told ABC News. The frequency and time frame of the alleged trips was not immediately clear.

It’s unclear whether prosecutors will ultimately gather enough evidence to bring charges against Abrego Garcia. The interview of Hernandez-Reyes, however, appears to be a new and aggressive step in the government’s efforts to gather potentially incriminating information about Abrego Garcia’s background — even as it resists calls for him to be provided typical protections to respond to such accusations through the American legal system.

A spokesperson for the Department of Justice declined to comment.

According to body camera footage of the 2022 traffic stop, the Tennessee troopers — after questioning Abrego Garcia — discussed among themselves their suspicions of human trafficking because nine people were traveling without luggage, but Abrego Garcia was not ticketed or charged. When asked to provide proof of insurance, Abrego Garcia told officers he would have to call his boss because he didn’t know where the insurance card was in the car. Audio from the police footage cuts out briefly after an officer asks Abrego Garcia who owned the vehicle.

The officers ultimately issued no speeding ticket and allowed Abrego Garcia to drive on with just a warning about an expired driver’s license, according to a report about the stop released last month by the U.S. Department of Homeland Security. The Tennessee Highway Patrol, in a statement last month, said troopers had contacted federal authorities before making that decision.

“The Tennessee Highway Patrol can confirm a 2022 traffic stop of Kilmar Armando Abrego Garcia, who was stopped for speeding on I-40,” a Tennessee Highway Patrol spokesperson said. “Per standard protocol, the THP contacted federal law enforcement authorities with the Biden-era FBI — the agency of jurisdiction — who made the decision not to detain him.”

An attorney for Abrego Garcia, Simon Sandoval-Moshenberg, said last week that he saw no evidence of a crime in the Tennessee traffic stop.

“But the point is not the traffic stop — it’s that Mr. Abrego Garcia deserves his day in court. Bring him back to the United States,” Sandoval-Moshenberg said. “I have represented Kilmar Abrego Garcia for more than a month, and this bodycam video is the first time I’ve heard his voice. He has been denied the most basic protections of due process — no phone call to his lawyer, no call to his wife or child, and no opportunity to be heard,” he said.

Sandoval-Moshenberg, when reached Monday by ABC News, declined further comment.

When details of the Tennessee traffic stop were first publicized, Abrego Garcia’s wife said her husband sometimes transported groups of fellow construction workers between job sites.

“Unfortunately, Kilmar is currently imprisoned without contact with the outside world, which means he cannot respond to the claims,” Jennifer Vasquez Sura said in mid-April.

The Trump administration in recent weeks has been publicizing Abrego Garcia’s interactions with police over the years, despite a lack of corresponding criminal charges. And now the incident in Tennessee nearly three years ago is under renewed scrutiny by the Justice Department, sources tell ABC News, just as the litigation over his erroneous deportation enters a critical stage.

The administration faces deadlines this week to answer discovery requests about what steps officials have taken to comply with a district judge’s order — affirmed by the US Supreme Court — to facilitate Abrego Garcia’s return to the U.S. Four U.S. officials are also set to be deposed this week by lawyers for Abrego-Garcia.

Abrego Garcia’s expulsion in March to El Salvador violated a U.S. immigration judge’s order in 2019 that shielded him from deportation to his native country, according to immigration court records. The judge had determined that Abrego Garcia would likely face persecution there by local gangs that had terrorized him and his family.

Abrego Garcia was initially sent to El Salvador’s notorious CECOT prison but is now believed to be held in a different facility.

Last month, after Abrego Garcia’s family filed a lawsuit, U.S. District Judge Paula Xinis ordered the Trump administration to facilitate his return to the U.S. The Supreme Court affirmed that ruling on April 10.

Hernandez-Reyes, who was not present during the 2022 Tennessee traffic stop, was charged in 2020 in a 7-count federal indictment for unlawful transportation of undocumented immigrants within the U.S. According to a criminal complaint, Hernandez-Reyes had rented a minivan that was pulled over by police in Gautier, Mississippi, and found with a total of nine undocumented occupants. Abrego Garcia was not among them.

Hernandez-Reyes allegedly admitted he was in the U.S. illegally and told federal investigators from the Department of Homeland Security that he had previously lived in Maryland but had since moved to Houston. He said he operated a Texas-based business transporting people throughout the U.S. for $350 per person. In June 2020, he pleaded guilty to a single count of unlawful transportation of an alien and was sentenced to 18 months in prison and subsequently deported, according to court records.

He was found back in the U.S. in late 2022 when he was charged in Montgomery County, Texas, with illegal discharge of a firearm, according to state court records.

After serving time in Texas he was charged federally with illegally reentering the U.S. after previously being convicted of a felony. He pleaded guilty and was sentenced to 30 months.