One of the world's most Catholic countries is also the most dangerous to be a Catholic priest.

Mexico's population is 81 per cent Catholic, according to the CIA Factbook and Pew Research Centre. Only Brazil boasts a higher number of Catholics.

But this weekend a third priest in a week was found dead. Jose Alfredo Lopez Guillen's body was discovered near the town of Puruandiro in Michoacan state. He is the 15th priest to have been killed since 2012 when President Enrique Peña Nieto's six-year term began, a 100 per cent increase compared to the former President Felipe Calderón.

But the figures point to an even more concerning trend of gradually increasing violence against clergy.

Since 1990, 52 priests have been killed, according to a report by Mexico's Catholic Multimedia Centre (Centro Católico Multimedial – CCM) which monitors violence against clergy. But of those murders, 40 have occurred in the last decade alone.

Murdered Catholic priests in Mexico may be symbolic of wider violence across the country as the war on drugs continues. A spike in priest killings in 2006 coincided with a wholesale increase in casualties as the Mexican military began its attempt to crush drug-related violence. "Priests are not the only martyrs in Mexico," said one missionary working in Mexico.

Jorge Eugenio Hernandez Trasloheros, a professor in Latin American studies at the University of Mexico, told Christian Today it was "not strange that priests suffer the same fate of the people". He said sometimes priests were targeted because of money within the parish alms system but more often priests were "very tight to the people" and the killings stoked fear.

"Mexican priests are leaders in their communities. They are no saints but they usually do their job very well. It is not strange that they are a target of the gangs. The criminals want people isolated and full of fear," he said.

But Omar Sotelo, a priest and director of CCM, said clergy attract particular violence because they preach against injuctice and violence. "They're defending migrants, they're against drug trafficking," he said when his report was launched in February 2016. "And the priests often know who the criminals are, having seen them grow up in the towns. Eventually, some criminals can see that as a threat."

He went on to say that older drug lords identified as Catholic but the younger generation of crime groups are "so dehumanised they target just about anything".

But the idea Catholic clergy are merely victims of a holy war against drugs is not universally accepted. During Pope Francis' visit to Central American in February, he gave what many saw as a roasting to the Catholic hierarchy.

Before Mexico's top bishops he called on priests to fight against an "insidious threat" and told bishops they had lost their way amid "gossip" and "slander". He urged them to "begin anew" as he said the religious authorities had engaged in "conceited schemes of careerism" and "empty plans for superiority".

He said: "Be vigilant so that your vision will not be darkened by the gloomy mist of worldliness; do not allow yourselves to be corrupted by trivial materialism or by the seductive illusion of underhanded agreements; do not place your faith in the 'chariots and horses' of today's pharaohs."

Roberto Blancharte, a scholar at the Colegio de Mexico, said he had never seen such a "scolding so severe, so drastic, so brutal to any bishops' group", according to the New York Times.

Blancharte, an expert in the Mexican church, said there was a deep divide between the Church's hierarchy who tend to live in luxury and mix with corrupt politicians, and its clergy, who rub shoulders with the country's poorest.

David Shirk, director of the Justice in Mexico Project at the University of San Diego, agreed. "I don't think anyone has dared to criticize the Catholic Church so vocally and so openly in recent times. And arguably it could have only come from the pope himself," he said according to the LA Times.

"The church's leaders have basically rested on their laurels, and in the worst cases have been as corrupt as the rest of Mexico's political leaders."

The disparity has not gone unnoticed by priests on the ground. "They never gave me support, not even words of inspiration: 'We're with you'," Father Alejandro Solalinde in Oaxaca said of the Mexico City bishops, according to the paper. "I would have loved that."

The bishops' reluctance to support or engage with clergy fighting against drugs has raised suspicion that some may be in the pockets of drug traffickers or politicians wanting to dumb down reports of violence.

The belief church leaders have cowed to pressure is widespread among parishes and the silence over murdered priests only fuels this perception. "When a priest gets killed, it should be a rallying cry," said Shirk. "We should know his name. He should be a martyr."