The daily newspaper Reforma reported 12,359 drug-related killings last year, a 6.3 percent increase from the previous year.
Other media reported similar numbers, The Washington Post reported Tuesday. For example, the Daily Milenio recorded 12,284 drug-related deaths last year.
A spokesman for President Felipe Calderon said the government would release its figures later in January, the Post reported.
Reforma reported 1,079 bodies exhibited signs of torture. Beheadings were nearly 600, up from 389 in 2011. Reforma also reported more women were victims of drug violence, with more than 900 slain last year. The newspaper did not provide a count of the number of children killed.
The Post said the homicide rate seemed to be down by about a third in Ciudad Juarez, Baja California and Tijuana. However, Chihuahua, Coahuila, Nuevo Leon, Tamaulipas -- Mexican states abutting Texas -- were the most deadly and violence spread to the state of Veracruz.