The photojournalist, who worked for the investigative magazine Proceso, was found dead along with four other people in a flat in Mexico City, according to media reports. Ruben Espinosa had reportedly recently moved to the city from the eastern state of Veracruz where he said he had been threatened and harassed.
Proceso was quoted by media as saying that the killings were discovered in the Narvarte neighbourhood of Mexico City a day after Mr Espinosa's family lost contact with him. The other four victims were all women. Three of them had lived in the apartment and the fourth was a domestic employee, the city prosecutor's office said.
Officials said Proceso said Mr Espinosa had suffered two gunshot wounds, reports added.
Sources: BBC, El Pais