A judge in Mexico has issued arrest warrants for 20 people in the death of the son of poet Javier Sicilia and six others, officials said. The warrants are the latest move in the high-profile case in Mexico's war on drugs, CNN reported Monday. "These subjects are suspected in kidnapping, homicide and other crimes against Juan Francisco Sicilia Ortega" and six others, the Mexico's attorney general's office said in a statement.The victims were found inside a car in the central Mexican town of Cuernavaca March 28. Investigators believe they suffocated because masking tape was wrapped around their heads and faces. Investigators suspect members of Mexico's Pacifico Sur cartel committed the murders. Sicilia's attorney, Julio Hernandez, said Sunday police were still looking for one person directly involved in the case. Authorities offered a $25.5 million reward for his capture. Sicilia, the poet, has become one of the most outspoken critics of Mexico's drug war and widespread drug-related violence. In a meeting with Mexican President Felipe Calderon last month, Sicilia asked for a moment of silence for the victims of "an atrocious and senseless war."