Police in Guatemala raided five regional offices of British aid agency Save the Children on Monday as part of an investigation into alleged child abuse.
Prosecutors requested information from US authorities in April about the alleged involvement of the organisation in smuggling children across the border, according to local media.
Save the Children said it was "aware of the activity" at their offices, and denied the prosecutors' allegations.
The prosecutor in charge of the case, Rafael Curruchiche, and the country's attorney general, Consuelo Porras, have previously been sanctioned by the United States and the European Union for attacks on democracy.
Curruchiche said the searches were being carried out in different regions of the country as part of a "transnational investigation of great importance", in a video statement on X.