The U.S. government has denied financial support to the family of a federal agent who was severely wounded in a 2011 ambush by a Mexican drug cartel but at the same time has subsidized housing expenses for the family of a hit-squad member who assisted in the shootout that left another officer dead.

The Immigration and Customs Enforcement special agent who survived the attack, Victor Avila, said the Department of Homeland Security refused to fund hotel, travel, and per diem expenses for his wife and two children during the two-week trial of two men accused in his attempted murder, which began in Washington, D.C., this week. DHS told Avila it did not have a "funding mechanism" to pay for the expenses.

Avila ultimately fronted the costs for his family to accompany him during the trial after raising safety concerns to DHS and Department of Justice officials.

"I couldn't fathom leaving them in Texas while I'm testifying against a cartel and risk their security while they are back home," he said. "It's not so much the defendants I'm worried about, but those loyal cartel members or individuals on the periphery who want to finish me off or harm my family."

DOJ meanwhile extended parole to the family of a former cartel member who pleaded guilty to participating in the ambush. The government has paid for the family's relocation and housing fees for at least the past year, according to Avila, who said the U.S. Office of the Attorney General confirmed the arrangement to him in December 2016.

"I'm thinking, wait a minute—you've paroled the family of a defendant who's been in this country for over a year now and has incurred the costs of bringing his family members to the U.S. for protection, yet you can't pay for my family to be in a hotel for two weeks for a trial?" Avila said. "You can only imagine my disgust."

The revelations come as Avila is set to testify for the first time in federal court in Washington about the 2011 ambush that nearly killed him and murdered his partner, ICE special agent Jaime Zapata.

Avila and Zapata were traveling on a highway near San Luis Potosi, Mexico, on Feb. 15, 2011, as part of a DHS mission, when a convoy forced their vehicle off the road. Gunmen, who were later identified as members of the Zetas narcotics trafficking cartel, surrounded their armored Suburban and ordered the agents to step out in an attempt to steal the vehicle.

The agents refused and identified themselves as American diplomats, but as Zapata placed the SUV in park the doors automatically unlocked. Cartel members immediately opened fire into the vehicle and struck both agents. Zapata bled to death at the scene. Avila was shot three times, suffering critical wounds, but survived.

Zetas cartel commander Julian Zapata Espinoza pleaded guilty to participating in the attack in May 2013, along with three other members of the drug cartel hit squad. A fifth member pleaded guilty to assisting cartel members after the ambush. All face up to life in prison.

The two defendants on trial this week—Jesus Ivan Quezada Piña, 28, and Alfredo Gaston Mendoza Hernandez, 33—were extradited to the United States in 2015 on charges of killing Zapata and attempting to kill Avila. The five former cartel members who have pleaded guilty are expected to testify against Piña and Hernandez in the coming days.

It is customary for the U.S. government to offer parole to the immediate family members of witnesses who are extradited to the country to offer testimony if federal officials assess there is a real or perceived threat to those individuals. The defendant could have also requested the government to parole his family into the country as part of an agreement with the United States, according to a former ICE agent.

Federal officials refused to identify to Avila which of the five defendants who have pleaded guilty to participating in the ambush had received parole for his family. DHS and ICE declined to comment. DOJ said it could not comment on ongoing investigations.

Avila said the entire process has been baffling.

He said DOJ denied funding for his family's expenses two weeks before the trial, after he had received several assurances from the victim witness coordinator of the U.S. Attorney's Office that all fees would be taken care of.

The government told him to seek reimbursement for out of pocket expenses from the Texas Crime Victims' Compensation Program, a state-run fund designed to financially aid victims of crime. He is expected to front all costs for his family's travel, lodging, and daily expenses for the duration of the trial. Avila said he is still not sure if the Texas program will cover all his family's costs.

"I've explained to the DOJ that I'm a witness for the federal government, not the state of Texas, but they're indifferent," Avila said. "Over the past six years, there's never been an effort by the government just to take care of us. We never expected any special treatment, we just wanted protection."