A journalist with Mexico City daily Punto Critico and the radio program "Voces del mediodia" (Voices of Midday) has been missing since May, his family said.
Federico Manuel Garcia Contreras has not been heard from since shortly after his arrival in the central town of Tanquian de Escobedo, in San Luis Potosi state, for an assignment, Africa Garcia, one of the reporter's daughters, told Efe.
She said that her father had met with the local police chief, Jose Alberto Troas, immediately after arriving from Mexico City.
The daughter said Garcia told his family by phone that he was well but that he had had an argument with Troas after the police chief denied him permission to conduct some interviews, saying it was too dangerous.
"We didn't hear from him again (after that) and my sister and I decided to go to Tanquian de Escobedo, where commander Troas said my father had not requested any interviews, although he said he was arrested on May 18 in an inebriated state along with another drunk," she said.
The police chief "said my father was only detained for two hours and was immediately released ... We also went to the hotel where he was staying, but the woman (in charge) told us he had not returned since the day of his arrival and his luggage was intact in the room."
"We think this whole case is strange and call on the authorities to immediately respond to our complaint," the daughter said.
She said that the family reported the case Monday to the Special Prosecutor's Office for Crimes against Freedom of Expression.
Paris-based press freedom watchdog Reporters Without Borders, known by the French initials RSF, said in a statement Friday that the circumstances surrounding the reporter's disappearance are "suspicious."
It said a doctor who examined Garcia after he allegedly disrupted a teachers' meeting found no sign of inebriation. RSF also said Troas initially told the reporter's daughters that he had ordered officers to take him to his hotel but later changed his story and said the man chose to return there on his own.
"It is not yet clear whether Garcia's disappearance is linked to his work but it is known that he identified himself as a journalist on his arrival in the town where he went missing," the press freedom watchdog said.
"The contradictory statements by the local police, who supposedly arrested him on May 18, need urgent clarification and should be a priority of the federal investigation. Did Garcia witness something compromising in a region where organized crime holds sway? The investigators must not ignore any possibility."
News of Garcia's disappearance surfaced after the federal government enacted a decree to boost protection for journalists and human rights defenders in Mexico.
This is the second case of a missing reporter in less than a month in Mexico - one of the world's most dangerous countries for members of the media.
Stephania Cardoso, a crime reporter for a newspaper in the northern state of Coahuila, and her two-year-old son went missing on June 8, although she said in a radio interview a week later that she was in hiding and asked the government for protection.
According to the National Human Rights Commission, Mexico's equivalent of an ombud's office, 82 journalists have been murdered in the country over the past 12 years and more than 16 others are missing and feared dead.
RSF says nearly all of those crimes have gone unpunished.
Most of the violence against journalists is thought to come from Mexico's powerful drug cartels and corrupt or abusive public officials. EFE