Mexican authorities say they have dealt a debilitating blow to major organised crime in the west of the country after apprehending the leader of the cult-like, pseudo-Christian La Familia cartel.

José de Jesús Méndez Vargas, known as El Chango, or The Monkey, was arrested in the central state of Aguascalientes without confrontation or casualties, according to federal security spokesman Alejandro Poire.

President Felipe Calderón lauded the arrest on Twitter, calling it a "big blow" to organised crime. After the death of La Familia founder and leader Nazario Moreno González in December, Poire said Méndez Vargas was the last remaining head of a criminal group responsible for homicides, kidnappings, extortion and corruption.

The Mexican attorney general's office said Méndez Vargas was "responsible for the transfer and sale of cocaine, marijuana, crystal methamphetamine in various states of Mexico and the US". He is also accused of having masterminded the kidnappings and killings of rival gang members. The government had offered a $2.5m reward for information leading to his capture.

La Familia first appeared four years ago when it rolled five severed heads into a Michoacán nightclub, vowing to protect local citizens from rival cartels. La Familia was part of the Gulf Cartel but later became an independent drug-trafficking organisation, which ignited a rivalry between the two gangs.

Moreno, the leader, set a code of conduct for its members that prohibited the use of hard drugs or dealing them within Mexican territory, even as they gruesomely decapitated foes and sold huge amounts of cocaine and methamphetamine.

"They believe they are doing God's work, and pass out Bibles and money to the poor," according to a US drug enforcement administration profile. "La Familia Michoacána also gives money to school and local officials."

Moreno was killed in December during two days of shootouts between La Familia and federal police. After his death, La Familia split into warring factions, causing increased bloodshed in western Mexico.

Poire told reporters that with Méndez Vargas's arrest, 21 of the country's 37 top drug traffickers have been apprehended or killed since 2009. More than 35,000 people have died in drug violence since, according to government figures. Local media say the number is closer to 40,000.

Meanwhile, officials in the northern Mexican city of Durango say they have found 14 more bodies in a mass grave, adding to the 250 corpses discovered since April.

Police have revealed no motives for the killings, but officials say the mass murders are the result of an internal power struggle within the Sinaloa drug cartel, Mexico's most powerful gang.