MEXICO CITY – One of the best-known leaders of Mexico’s vigilante “self-defense” movement has been arrested on suspicion of participating in a double homicide, raising new doubts about the federal government’s strategy of partnering with armed campesino groups in the fight against a powerful drug cartel in Michoacan state.

Hipolito Mora, a lime grower who gained fame for leading one of the first local uprisings of autodefensa groups early last year in the small city of La Ruana, was arrested Tuesday by state officials. The state prosecutor’s office said Mora and other members of his group were suspected of “co-participation” in the slaying of Rafael Sanchez Moreno and Jose Luis Torres Castaneda, whose burned bodies were discovered on Saturday.

Many of the details in the killings remain murky, but the slayings occurred as tensions had risen between Mora’s group and another local vigilante faction, perhaps because of an inter-family spat over the love life of Mora’s niece. That kind of grudge is not uncommon in Michoacan, where a complex tangle of multigenerational blood feuds can be just as deadly as the dynamics of the drug game.