Reporter Victor Manuel Baez Chino covered the crime beat in Xalapa, the state's capital, for the local edition of the national newspaper Milenio as well as for a news website called Police Reporters.
Veracruz state spokeswoman Gina Dominguez said Baez Chino was reported kidnapped outside the offices of the website in Xalapa as he left work late Wednesday. His body was found dumped on a street in the city early Thursday.
Authorities said a note was attached to Baez Chino's corpse signed by the Zetas.
"This is what happens to those who betray us and be clever, Sincerely the Zetas," the letter reportedly said.
Baez was the fifth journalist to be slain this year in Veracruz, one of the states most affected by drug trafficking violence as the Zetas battle with their rivals, the Gulf cartel.
Since 2000, 81 journalists have been killed and 16 kidnapped in the drug war, the Mexican government's human rights commission says.
The Mexican military announced Thursday that troops early this week captured Gregorio Villanueva Salas, the Zetas' chief of production and distribution of pirated goods to Mexico's border region.