The number two official in Mexico's troubled western state of Michoacan has been arrested while authorities investigate alleged ties with organised crime.
The attorney general's office said in a statement on Saturday that it "found possible contacts" between Michoacan's secretary of the interior Jesus Reyna and "criminal organisations."
A judge granted a request by prosecutors to place him under detention without charge for up to 40 days in order to "deepen the investigation", the statement said.
The attorney general's office had revealed on Friday that Reyna had been taken to Mexico City to undergo questioning.
The statement did not name a criminal organisation but civilians who formed vigilante militias in Michoacan have accused Reyna of having links to the Knights Templar drug cartel.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
A March 2012 Michoacan public security document obtained by AFP alleges that Reyna had held three meetings with Knights Templar leader Servando Gomez, alias "La Tuta".
Reyna has denied the accusations.
Vallejo announced on Saturday that he had decided to fire Reyna, saying that while his deputy had been an "efficient collaborator," he was not "exempt from answering for the personal conduct" for which he is under investigation.
The government of President Enrique Pena Nieto has stepped up a crackdown on the Knights Templar this year in Michoacan, a state that was once treated by the cartel like a fiefdom.
Pena Nieto deployed 10,000 troops and federal police in January.
After initially tolerating the vigilantes, the government urged them this week to drop their weapons, saying the authorities have fulfilled their demands to take down Knights Templar leaders.
Last Monday, marines killed Knights Templar financial boss Enrique Plancarte in a shootout in central Mexico.
The cartel's founder, Nazario Moreno, was killed by troops in Michoacan in March, leaving "La Tuta" Gomez as the last top leader who remains at large.
