A former youth care worker at a facility where migrant children were kept after crossing into the United States has been charged with sexually abusing eight boys in the care of the government, according to court fillings.

Federal prosecutors laid out the case against Levian D. Pacheco in a court filling, submitted on July 30, that alleges he sexually abused eight minors between the ages of 15 to 17 in the Casa Kokopelli shelter in Mesa, Arizona. The facility is run by Southwest Key Programs, which has a contract with U.S. Department of Health and Human Services.

The filling alleges the inappropriate contact took place between August 29, 2016, and July 24, 2017.

Pacheco, 25, is charged with eight counts of abusive sexual contact of a ward and three counts of sexual abuse of a ward. The charges against Pacheco were first reported by ProPublica.

A sign stands outside Southwest Key-Nueva Esperanza, in Brownsville, Texas, a facility that shelters unaccompanied immigrant children on June 20, 2014. Eric Gay / AP file

On Thursday, Southwest Key Programs, which operates Casa Kokopelli, said in a statement that any employee accused of abuse is immediately suspended and law enforcement notified, adding that is what happened in the case of Pacheco.

"We educated every child in our care upon arrival to the facility of their right to be free from abuse or neglect in this program and this country," the statement reads. "This message is repeated to the children throughout the duration of their stay at our shelters."

The statement also says that staff at the facility go through background checks and that phones available to children in the shelter are pre-programmed to call 911, Child Protective Services and the Office of Refugee Resettlement.

It is unclear if the victims cited in the case entered the United States alone or if they were separated from their families upon entering the United States.

The court filling alleges the abuse took place eight or more months before the Trump administration's short-lived policy of separating families at the U.S.-Mexico border. That policy separated 2,551 migrant children from their parents. As of Friday, 572 children in U.S. custody remained separated from their families.

Many of the 2,551 children separated from their parents were held at Southwest Key facilities, according to the Associated Press. The AP also reported that another Southwest Key worker at a different facility, Fernando Magaz Negrete, is suspected of molesting a 14-year-old immigrant girl in June.

Pacheco was arrested and indicted in mid-August 2017 on charges of touching the genitals of at least three boys in the custody of the Casa Kokopelli facility, where he had been employed since May 2016, according to ProPublica.

Since then, the case against Pacheco has grown to include allegations that he touched the genitals of six victims over their clothing and that he performed oral sex on two victims. The July 30 filing also alleges that Pacheco attempted to have a victim penetrate him anally.

The case was initially investigated by local authorities, according to ProPublica, but is now proceeding in a U.S. District Court in Phoenix.

The most recent filing in the case, submitted on Friday, was made by attorneys representing Pacheco, asking the court to deny entering Pacheco's positive HIV status into evidence. The defense argued in the filing that "no conduct alleged in the indictment ... carries any realistic risk of HIV transmission."

Benjamin Good, the federal public defender representing Pacheco did not immediately respond to a request for comment made by NBC News, but told the Associated Press, “We are looking forward to defending Mr. Pacheco in court.”

In a report published in July, ProPublica found that at least 125 calls reporting sex offenses at shelters that primarily serve immigrant children had been made since 2014. That report included details of a third Southwest Key employee at a Tucson, Arizona, facility, in which authorities said an employee touched a 15-year-old Honduran boy’s penis from outside his clothing. That employee was fired and later convicted.