by Caroline May 2 Sep 2014, 1:27 PM PDT

An investigation into the treatment of the unaccompanied minors detained illegally entering the United States and in the Department of Homeland Security’s custody was unable to substantiate some of the allegations of misconduct made by advocacy groups on June 11.

In a memo to DHS Sec. Jeh Johnson released Tuesday, John Roth, the Inspector General for the Department of Homeland Security, said officials made 57 unannounced visits to 41 Customs and Border Protection locations, during which time investigators “did not observe misconduct or inappropriate conduct by DHS employees,” and no other complaints were made during interviews with the migrant children.

Roth noted that the investigations are still ongoing but that food services and sanitation had gotten better at the facilities and that the most common complaint among the children was the temperatures of the facilities — either too hot or too cold — adding that all facilities have blankets available.

The report notes that “In several Border Patrol stations, agents told us there is insufficient staff to process a large influx of UAC and families, and also conduct the normal level of enforcement operations.”

The memo comes after the American Civil Liberties Union and other advocacy groups accused DHS with 116 allegations of misconduct.

Roth wrote that of the 16 allegations the OIG investigated, his office was “unable to substantiate any of the allegations” and “continue to monitor the remaining 100 allegations being investigated by Immigration and Customs Enforcement (ICE) Office of Professional Responsibility (OPR), Customs and Border Protection (CBP), Office of Internal Affairs (IA), and the DHS Office for Civil Rights and Civil Liberties (CRCL).

The report comes in the wake of a mass influx of unaccompanied minors illegally entering the United States. From October 1 to July 31, approximately 63,000 unaccompanied minors have been detained illegally entering the United States. The vast majority of the unaccompanied minors have been from El Salvador, Honduras, and Guatemala.

The memo notes that officials also made three unannounced visits to the Federal Law Enforcement Training Center (FLETC) in Artesia, New Mexico, which houses family units. There Roth wrote that conditions have been “improving;” however, challenges remain.

“Family unit illnesses and unfamiliarity with bathroom facilities continued to result in unsanitary conditions,” the memo read. “DHS employees told us the contracted cleaning service is inadequate.”

Overall, Roth sounded a positive tone in a statement released with the memo.

“I’m pleased with the progress CBP has made in dealing with this unprecedented crisis, although some challenges remain” Roth said in a statement. “We will continue with our proactive oversight and report the results on a monthly basis, or as events dictate.”