OTTAWA -- A man accused of slaughtering villagers in Guatemala using a grenade, gun and sledgehammer is fighting Canada's attempt to revoke his citizenship.

Jorge Vinicio Sosa Orantes denies he concealed participation in a 1982 massacre by the Guatemalan military when he obtained Canadian citizenship a decade later.

In documents filed in Federal Court, Sosa Orantes says he was not even in the village of Las Dos Erres when the events took place.

He paints himself as an upstanding instructor at a military training school during the period in question, working with local communities in Guatemala to build good relations.

Sosa Orantes, 59, is serving a 10-year sentence for immigration fraud in the United States, where he also held citizenship until it was revoked in 2014.

In the early 1980s, the Guatemalan military junta began a ruthless campaign against guerrilla groups that wiped out 440 villages, killing over 75,000 people and displacing more than 250,000, the Canadian government says in documents filed in Federal Court.

Canada says Sosa Orantes was a senior member of a military special forces group that led a mission to Las Dos Erres in December 1982 to interrogate inhabitants after some military rifles were allegedly stolen during a guerrilla ambush of troops.

Military members killed at least 162 civilians, including 67 children. Women were raped and children were thrown into an 18-metre dry well.

"The members of the special forces group killed their victims by hitting them on the head with a sledgehammer, by hitting their heads on a tree, by shooting them, or by slitting their throats," the federal submission says.

"In other cases, victims were simply thrown into the well while they were still alive."

At one point, Sosa Orantes fired his rifle into the well, then tossed in a grenade, the documents say.

In supervising the killings at the well, he mocked subordinates "who showed any hesitation to commit the murders."

Sosa Orantes is representing himself in the Federal Court case, filing documents -- including a statement of defence in sometimes fractured English -- from a Phoenix, Ariz., prison.

"I was not in Las Dos Erres," he writes.

Sosa Orantes says that in late 1982 and early 1983 he was busy travelling to several towns as part of a goodwill effort, handing out notebooks, pens, chalk, educational games and sports equipment.

"I distributed material to more than 20 schools in the area. I had no information about Las Dos Erres and other ... operations due to the fact that I was a subordinate."

Sosa Orantes left Guatemala for California in 1985. After being denied asylum in the U.S., he visited the Canadian consulate in San Francisco to seek haven in Canada. He was granted refugee status, later becoming a permanent resident and citizen of Canada.

The federal government argues Sosa Orantes failed to disclose details of his military involvement that would have made him inadmissible to Canada.

In his court filing, Sosa Orantes insists he disclosed his military background and "had nothing to hide."

Sosa Orantes married an American woman and attained U.S. citizenship in September 2008.

In 2010, the U.S. discovered he had committed immigration fraud by concealing his past. He was arrested the following year in Lethbridge, Alta., while visiting family.

In ordering his extradition to the U.S. to face trial, the Alberta Court of Queen's Bench said the evidence establishes Sosa Orantes was one of the commanding officers who decided to murder the villagers and that he "actively participated in the killings with a sledgehammer, with a firearm and a grenade."

"It is difficult for this court to comprehend the murderous acts of depraved cruelty on the scale disclosed by the evidence."