The Mexican authorities made a surprise discovery on Sunday after finding a large number of migrants inside a truck.
The vehicle had been travelling from the state of Tabasco to the neighbouring region of Chiapas in southern Mexico.
The authorities investigated the truck after hearing voices coming from the back of it.
The prosecutor for the area said a total of 112 migrants had been living in "disastrous conditions" in the back of the truck.
Among the people found were four newborns, and a number of the group had come from countries like Honduras, El Salvador, Ecuador, and Guatemala.
The driver has been arrested, and it is not known if he has been charged with any crime.
Migrants desiring to reach the United States often travel through Mexico, and NGO Doctors Without Borders say they can find themselves vulnerable on such journeys.