Fellow party members of a slain Mexican congressman from southern Guerrero state published a letter in newspapers Monday demanding a local politician be investigated in the case.
Efren Leyva, president of the Guerrero chapter of the Institutional Revolutionary Party, or PRI, urged authorities to investigate state Rural Development Secretary Socorro Ramirez in the killing of Congressman Moises Villanueva and his driver.
The outcry by state PRI members hasn't been echoed elsewhere in Mexico, where the slaying was viewed as a local crime in a state rife with political and drug violence.
Residents spotted the badly decomposed bodies in a river in the town of Huamuxtitlan and alerted police Saturday. The dead men had been missing since Sept. 4, after leaving a party held by a fellow PRI member in Villanueva's district.
Villanueva, 46, replaced Ramirez in Congress after he left the PRI earlier this year to join the leftist Democratic Revolution Party shortly before being named to his state government post.
"We publicly demand Socorro Sofio Ramirez Hernandez, rural development secretary for the government of Guerrero, be investigated because he is known to have pressured Villanueva at various times to subordinate him to his personal interests," Leyva wrote.
Ramirez denied any involvement and said he would sue PRI members for slander.
"PRI members in Guerrero are being too politically perverse," Ramirez told Milenio Television on Monday.
Guerrero state Attorney General Alberto Lopez said Ramirez was not being investigated in the case because there was no evidence pointing to his involvement.
Lopez also said police had not determined a motive in Villanueva's killing. He said that despite claims by PRI members, there was no proof that the congressman was kidnapped for ransom.
Guerrero is a drug-plagued southwestern state that include the Pacific resort of Acapulco and it has seen a series of killings of politicians and political violence the last few years.
Two years ago, gunmen killed the state legislature's presiding lawmaker. The body of leftist Armando Chavarria, who was poised to be the next governor, was found in the passenger seat of a vehicle in the state capital of Chilpancingo. The case hasn't been solved.
In 2007, Guerrero state lawmaker Jose Jorge Bajos of President Felipe Calderon's National Action Party was shot to death. Authorities blamed the politician who had been selected by Bajos as his alternate in the event he left office, accusing her of paying a hit man to kill Bajos so she could take the post.
"The general sense of impunity (in Guerrero) is even more so" than in the rest of Mexico, said John Ackerman at the legal research institute at the National Autonomous University in Mexico City.
Those crimes "are seen as issues of local politics," he added.