Mexico’s local authorities’ association say a mayor allegedly threatened by drug gangs in the western state of Michoacan has been killed.
Ygnacio Lopez Mendoza, who headed the small town of Santa Ana Maya, was found dead in his car on Thursday.
He had been speaking out about the Knights Templar cartel and had recently ended an 18-day hunger strike demanding more funds for his municipality.
On Twitter, the former President Felipe Calderon demanded a full investigation.
Mr Calderon also linked the crime to the Knights Templar drug cartel, publishing a quote allegedly by Mr Lopez Mendoza, who was a qualified doctor.
“For every building work, we have to pay the Knights Templar 10%. All of us, Michoacan mayors, have this problem,” the former president tweeted.
In a letter to other mayors, the association of local authorities said that Mr Lopez Mendoza’s death “was not an accident”.
Early reports on Thursday suggested he might have been killed in a car crash.
“According to information given by his [Mr Lopez Mendoza’s] family, the doctor got home at about midnight and as he drove his car in, he was abducted by a group of people,” the letter read.
In an interview with a local radio, the executive-secretary of the association said the politician was tortured.
Ricardo Baptista Gonzalez told MVS that Mr Lopez Mendoza got a call from the drugs cartel demanding “more pay”, after the federal government agreed to disburse more funds for his municipality.
In May, President Enrique Pena Nieto sent in a general to take over police and military operations in the western state.
Self-defence vigilante groups have formed in several towns in the region vowing to fight the violence, kidnappings and extortion carried out by drug cartels.
Some 60,000 people have died across Mexico since 2006 when the previous government under Felipe Calderon deployed the military against the drugs gangs.