Excelsior reports a thriving business in the state of Chiapas (bordering Guatemala) of selling fake birth certificates to foreigners.

From Excelsior: “Authorities of Chiapas are investigating a network dedicated to the trafficking of birth certificates for foreigners in 12 border municipios, an operation that has resulted in 3 detentions…”
In Mexico, a municipio is a city or town with the area around it, and the jurisdiction of that government.
“…[T]he investigation began after irregularities were detected in the public registry of the Tzimol municipio..

So what foreigners are they selling them to?
“...[T]hese birth certificates are principally sold to citizens of Cuban and Haitian origin. The costs of the documents range from 1,500 to 2,500 dollars apiece.”
The article says “citizens of Cuban and Haitian origin”. It must mean Cuban citizens and Haitian citizens currently in Mexico. If they were Mexican citizens of Cuban or Haitian ancestry why would they want fake birth certificates? After all, the article calls them “foreigners” and the caption of a photo refers to “Haitian migrants”.
In the municipio of Altamirano they discovered over 1000 of these fake birth certificates in the registry system, and they didn’t even have signatures or fingerprints.

More than a dozen municipios in the border area are being investigated, and it’s supposed that public officials in public registries are involved.