The number of people in Mexico disappearing under suspicious circumstances, often related to drug violence, rose to 30,000 by the end of 2016, the National Human Rights Commission said on Thursday.
At the start of 2013, shortly after President Enrique Peña Nieto took office, the Mexican government reported there were 26,000 so-called "disappeared" people.
The Commission said the number of "disappeared" had risen to 30,000, with the drug-ridden northern state of Tamaulipas registering 5,563 missing, the highest state total.
It said six of Mexico's 32 federal entities failed to respond to its enquiries on the number of missing persons.
The Commission also said it had accounted for 855 mass graves across Mexico over the last decade, finding 1,548 corpses, the large majority of which were male. Just over half of those bodies have been identified, it added.
Well over 100,000 people have died in drug-related violence in Mexico over the last decade.