Ygnacio Lopez Mendoza, who headed the small town of Santa Ana Maya, was found dead in his car on Thursday.
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.
'No accident'
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.
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.
100 out of 113 Michoacan Mayors Pay Extortion Fees to Knights Templar
Most of the mayors in the municipalities of Michoacan are subject to extortion by Knights Templar and, according to unofficial tally of exofficials of the state, of the 113 municipalities in the state, at least 100 pay money to criminals so that their mayors can perform normal duties, unbothered by the cartel government sources of this entity revealed to La Jornada.
Governor Fausto Vallejo Figueroa said yesterday after the assassination of the mayor of Santa Ana Maya, Ygnacio Lopez Mendoza, however, for the mayors this is already such an old story. The threats, pressures and the terror of by capos and operators of organized crime in regions of this Michoacan.
The Knights Templar cartel, has pushed many mayors with their constant threat of kidnapping that they consider resigning. Aware of the intentions of the mayors, the regional heads of the criminal group have warned: If you're back out, you die.
these stories are told quietly about the drug traffickers in Michoacan who are destroying everything and control not just state politics but also a big slice slice of all economic activities: the planting of lemons, which is a life source in the community; avocado production, as well as livestock.
Nobody speaks of it, unless the condition is to ensure anonymity. Just mayors were elected in January this year, The Knights Templar sent armed cells to invite them for interviews with crime bosses. Those who refused, confirmed unofficial state government authority, were lifted by commands.
In all cases, demanded of the leaders were payment of municipal finance fees. If the councils did not have sufficient resources, then the payment would be paid through the allocation of public works and sliced from money deposited by state authorities.
Bring your treasurer, they would have told the councilors, confided one of the sources consulted by La Jornada . None of the region Cuitzeo, escaped this instruction. It is estimated that at least a hundred of the 113 councilors pay cuotas to these criminals.
In 40 municipalities in the regions of Cuitzeo, and Valle de Morelia sends a bastard said a legislator, whose identity was reserved for fear of reprisals. He noted that when the PRD recovered three mayors, after exhausting legal proceedings, "and since winning mayors attended the meeting with the heads of the narco, one wanted to crack and give up, was warned: 'If you quit, you die . '
City officials claimed that when some mayors were abducted by criminals to force them to pay dues, they were terrified and suffered nervous shock.
Respondents know what happened to Ana Lilia Manzo, while serving as mayor of Cojumatlán de Régules, who about two and a half years to pay fee and resisted the criminals, and had an alleged car accident on August 28, 2013, whose injuries included the amputation of her legs.
Recently PAN Senator Luisa Maria Calderon said she has facts and dates cases of extortion practiced by organized crime to Michoacan mayors: they charge for each work, and have been told that if they have no time to reconcile their accounts until they will send people to be the balance the books.
Payments can reach a fifth of the total income they have for the municipal administration, although it depends on whether it is a large or small town.
"Drug traffickers know well when there are deposits and until they get someone leaked copies from the state government "revealed a municipal worker.
A state official reported that organized crime uses infiltrated women accountants operating as comptroller in municipalities. Entering offices normally, to review books, settle accounts make cash cut, and leave with the money.
In fact allegedly linked al narco , from 2005 to date mayors have been killed Fernando Chavez Lopez, Buenavista Tomatlán (2005) , Jose Vazquez Piedra, Turicato (2008) Manuel Octavio Carrillo Casillas, Vista Hermosa (2009), Gustavo Sanchez Cervantes Tancítaro (2011), Ricardo Guzman Romero, La Piedad (2011), Maria Sanchez Gorrostieta, Tiquicheo (2012)-after completing their management and after surviving two attacks-, and Ygnacio Lopez Mendoza, Santa Ana Maya (2013), and dozens of municipal officials and state and municipal police forces.
