The Mexican government has estimated that 26,122 people have gone missing since 2006, a period dominated by drug running violence.
The list, much higher than original estimates, includes more than 20,000 ongoing investigations but just over 5,000 still have to be verified.
The Human Rights Watch pressure group has said it found evidence “of disappearances involving State agents” and documented 250 cases that took place during the previous administration of President Felipe Calderon.
It also accused branches of the security forces of involvement, often at the behest of drug cartels.
The Human Rights Group is trying to determine which cases may be related to organised crime linked to the drugs scene or to re-location and migration.
The war on drugs by the Calderon regime in 2006 is seen to have led to a surge of drug-linked crime with an estimated 70,000 people dying and hundreds more going missing over the past six years, during which time government forces were patrolling the streets.
After coming to power in December last year, President Enrique Pena Nieto has fought organised crime and has created a new federal police force to help cut down murder rates.