MEXICO CITY—A member of former Mexican President Felipe Calderon's administration disputed on Friday that there is a list of 27,000 missing people as announced by the current government of President Enrique Pena Nieto.

Jose Vega, who was Calderon's coordinator of the National Security System, an entity responsible for collecting and analyzing security data, said that the only registry on disappeared people contains 5,319 names.

Some of the missing people are those whose disappearances are blamed on organized crime, but others include those who may have voluntarily stopped contacting their families, Vega wrote in a letter sent to Mexican and international media.

Vega said that it's up to state authorities to investigate missing person reports and to keep records on those people. He said the list that includes 5,319 people who went missing in the last decade is not complete because local authorities didn't send the federal government the requested information when Calderon's administration tried to compile a list.

This leads him, Vega wrote, to "categorically reject the existence of a list alluded to by national and international media and based on alleged leaks by the federal Attorney General's Office."

Lia Limon, deputy secretary for human rights at the Interior Department, told reporters this week that the government plans to unveil a database containing more than 27,000 records of missing people that were gathered by the federal Attorney General's Office. She said she had not seen it and did not have details of specific cases.

Limon made the comments the same day Human Rights Watch criticized Calderon in a report on disappearances in Mexico, saying he ignored the problem that the group called "the most severe crisis of enforced disappearances in Latin America in decades."

A Mexican civic organization released a database late last year that it said contained official information on more than 20,000 people who had gone missing in Mexico over the previous six years—the term of Calderon, who stepped up the government's campaign against drug cartels.

In posting the database on its website, Propuesta Civica, or Civic Proposal, said the information was collected by the federal Attorney General's Office during Calderon's administration.