Families of some of 42 suspected criminals killed in what Mexican authorities have described as a shootout are raising doubts about the official account, the Associated Press reported.

The country's Federal Police insisted on Monday that the death toll was the result of a three-hour gun battle at the Rancho del Sol in Michoacán state, which followed a report that the Ecuandureo facility had been taken over by armed men. They said one police officer also died in the incident, the newswire detailed.

Gathered at a local morgue, relatives of those killed said one body was missing an eye and had facial bruising, another had its teeth knocked inward and a third suffered a gunshot in the top of the head. They suspect that the lopsided death toll may be due to executions rather than a shootout with authorities.

"It was a true act of savagery. Our relatives are unrecognizable," an unidentified woman waiting for the release of her relative's corpse told teleSUR.

"This was not a clash, it was a massacre," another unnamed witness told the semi-official Venezuelan TV network.

But Enrique Galindo, the head of Federal Police, ruled out that possibility when he spoke to local media, the AP noted. "There was not one single execution, I can say that categorically," Galindo insisted.

The scene at the Rancho del Sol included a Black Hawk helicopter that hovered over the facility, and residents from the nearby town noticed a thick cloud of black smoke in the air in the direction of the violence, the Daily Beast described. The 42 killed were allegedly members of a crime syndicate that dominates the opium and methamphetamine production in the area.

National Security Commissioner Monte Alejandro Rubido said at a press conference that the suspects had opened fire on a government patrol, provoking a pursuit that led back to the 277-acre facility, the website added.

"The rest of the criminals inside the ranch started to attack the federal forces with intensity," Rubido said.

Authorities claimed to have seized arsenal of 36 assault rifles, two handguns, a .50 caliber sniper rifle and a grenade launcher, according to the Daily Beast.