(Adds details, background, context, comment from official)
MEXICO CITY, March 9 (Reuters) - A Mexican drug lord who had been reported dead more than three years ago was likely killed in a shootout with federal forces in western Mexico early on Sunday, a government official said.
Nazario Moreno, a leader of a powerful criminal gang that has ravaged the western state of Michoacan, was reported killed by the government in a firefight in December 2010. But his body was never recovered and he was widely believed to be alive.
Authorities were checking on reports that Moreno was shot dead early on Sunday during a gunfight in Michoacan, said the official, who spoke on condition of anonymity.
"Everything suggests, to a degree of certainty of around 98 percent, that it is this man (Moreno)," the official said.
If confirmed, the death of Moreno would be another victory for President Enrique Pena Nieto's government in its campaign to bring Mexico's powerful drug gangs to heel. The country's most wanted drug baron, Joaquin "Shorty" Guzman, was captured last month.
A government security spokesman said there was an exchange of fire between federal forces and suspected criminals but could not confirm Moreno had been killed. A spokeswoman for the state government of Michoacan also said there was no confirmation yet.
Moreno was a leader of a drug cartel known as La Familia, which fractured after his reported demise. Moreno's allies formed the most powerful faction of La Familia, and renamed themselves the Knights Templar after a medieval military order.
The Knights Templar had much of Michoacan under its control until local vigilante groups rose up against them at the start of this year and began to overrun the gang's strongholds.
The government has formed an uneasy alliance with the vigilantes despite concerns that the so-called self-defense groups had themselves been infiltrated by organized crime.
A number of officials in Michoacan told Reuters earlier this year that Moreno survived the 2010 shootout and continued to play a part in the activities of the Knights Templar.
A few days ago a top government official was asked about whether Moreno was dead or alive. "Proof that he is alive? Let me put it this way, there's no proof that he is dead," the official said, speaking on condition of anonymity.
Alfredo Castillo, the federal government's special commissioner for Michoacan, said this month the capture of a man believed to be a son of Knights Templar leader Servando Gomez had provided valuable intelligence to the authorities.
That information may have helped them track down Moreno.
Moreno was born in 1970 in an unruly part of Michoacan known as the Tierra Caliente (Hot Country), where traffickers have long grown marijuana and poppies to make opium.
Working as a laborer in the United States in the 1980s, Moreno converted to evangelical Christianity and when he returned home, he spread his version of the gospel within the drug trade.
In 2006, Moreno named his cartel "La Familia Michoacana" and in adverts printed in newspapers claimed his troops were good Christians who defended their kind even if they smuggled drugs.
La Familia was given a boost by the rising crystal meth trade, with smugglers bringing in precursor chemicals to Michoacan's Pacific port of Lazaro Cardenas.
The Knights Templar took a firm hold on Lazaro Cardenas and would go on to export iron ore from the port to China.
Federal police caught up with Moreno in 2010, when he was handing out Christmas presents of washing machines and cars in a festival in the village of El Alcalde.
Police who took part in the strike against Moreno said the 2,000 officers involved in the attack ran into hundreds of gunmen who blocked roads with burning cars and trucks.
In hours of fighting, five officers were killed, and police shot dead more than 50 gunmen, police said. The cartel carried many of those hit, including Moreno, into the hills. (Reporting by Dave Graham and Simon Gardner; Editing by Paul Simao and Mohammad Zargham)