David Muir Reports: Lawsuit to Be Filed Against Mexico for Human Rights Abuses Against Disabled

— -- Disability Rights International, an advocacy group that has teamed up with ABC News' David Muir to uncover youth, some with disabilities, living in deplorable conditions in government-funded facilities, has announced that it will move forward in its lawsuit at the Inter-American Commission on Human Rights against the government of Mexico for "allowing egregious human rights abuses against children and adults with disabilities to continue unabated."

In July 2015, after a visit by ABC News and Disability Rights International, Mexico City's Ministry for Social Development announced a ban on the use of restraints and cages for children under its care and said it would work to get many into homes.

"Effective immediately Mexico City will ban the use of restraints and cages," Secretary Jose Ramon Amieva of the Ministry for Social Development said at the time.

Last weekend, however, ABC News' Muir and Disability Rights International staff revisited several facilities and found little to no change. In one case, the site’s doors were closed in their faces.

"They signed documents. They made it look official before the cameras. They didn't do nothing," said Priscila Rodriguez of Disability Rights International.

Overnight, the Mexican government stated that it had made changes, however, sending ABC News a list of its accomplishments and reforms, including the banning of cages.

Last year, Disability Rights International, which has worked in Mexico for more than 20 years, released a report that detailed its findings after a year-long focus on the children, some with disabilities, growing up in state institutions. In its report, the organization said that it had obtained a so-called "black list" -- dated November 2013 and created by the Mexican government -- of 25 facilities where children continued to be left permanently, despite the Mexican government's declaring those sites abusive or in very bad condition.

Click here for more information on Disability Rights International.

During that visit last summer, ABC News along with Disability Rights International visited a site that featured a maze of locked doors with padlocks on every door and every window. Disability Rights International said that even though the Mexican government had placed the facility on its black list, the government's funding had kept the building going. Rodriguez said the public was not aware of this list.

At another site on the black list, ABC News and Disability Rights International found standing water and squalor.

Last weekend, ABC News returned to one institution where residents had been kept in rows and rows of cages. Last year, the director had invited the team back to see changes implemented after the ban.

However, when ABC News and Disability Rights International arrived, they were told by the deputy director that she needed the director, the organization's president and a lawyer present before they could enter. Although she said changes had been made in the institution, she would not allow ABC News or Disability Rights International five minutes inside. She then closed the facility's doors.

As she waited outside with ABC News, Disability Rights International's Rodriguez was sent a text by the Mexican government again denying entrance.

At another site, a facility director told ABC News that she was ready for change and that she needed help. She said, however, that since last year's visit, she'd gotten no help from the Mexican government.

In a news release today, Disability Rights International said its staff had been threatened Monday as the organization planned a news conference for today to announce its lawsuit.

"Threats began several months ago, but escalated last night via social media," Disability Rights International said.

Despite the threats, the news conference was held to announce the lawsuit.