COLUMBUS, Ohio - The government accuses a federally licensed firearms dealer from Youngstown of being part of an illegal scheme to sell 62 high-powered, military-grade, 50 caliber rifles to buyers in Mexico.

A federal indictment unsealed in Columbus charges Paul Groves with conspiracy to defraud the government and receiving an unregistered firearm.

According to the indictment, Groves operated High Powered Armory at 2500 Market Street on Youngstown's South Side.

Investigators say that Groves and Eric Grimes of Columbus sold rifles to a group of “straw buyers” in Indiana, who in turn, sold the firearms to people in Mexico who paid highly inflated prices.

The indictment lays out four occasions in 2015 where Groves allegedly met with the straw buyers at his Youngstown business and in Columbus to sell a total of 18 rifles for an average of $8,000 each.

During one of those transactions the straw buyer was accompanied by an undercover ATF agent.

The U.S. Attorney's office alleges that Groves provided false information for the purchase of firearms, fraudulently sold and acquired the semi-automatic firearms, and conspired to re-sell the guns to illegal buyers.

The unregistered firearm charge stems from an allegation that Groves obtained a 40mm caliber machine gun.

Grimes pleaded guilty on Wednesday to violating federal law covering the import and manufacture of firearms. He'll be sentenced later.

As for the alleged Indiana straw buyers, a federal grand jury in Indianapolis handed up a ten count indictment against four men and two women in February of last year.

That indictment recounts how the suspects visited federal licensed firearms dealers in Youngstown, as well as those in Pennsylvania and Illinois to purchase guns.

Members of the Indiana group then allegedly obliterated the serial numbers on the weapons and took them to the border town of McAllen, Texas, where the guns would be sold to the Mexican buyers.

The Youngstown purchases included Barrett M82 .50 caliber rifles and Gun Envy Mk46 .223 caliber belt fed semiautomatic rifles, according to the indictment.

The indictment does not identify who received the guns in Mexico, or how the weapons were put to use.

However, the government's General Accountability Office reported to congress in 1999 that .50 caliber semiautomatic rifles have been used in domestic and international criminal activity including terrorist groups, outlaw motorcycle gangs, international drug cartels, domestic drug dealers, religious cults, militia groups, potential assassins, and violent criminals.

A sealed indictment charging Groves was originally handed up in February 2016.

The superseding indictment issued on Thursday adds a provision stating that if he is convicted, Groves would have to forfeit any firearms confiscated during the investigation.

Before the superseding indictment was filed, Groves was scheduled to go on trial in Columbus on May 15.

The High Powered Armory made Youngstown headlines in 2012 when thieves broke in and stole 36 assault rifles and handguns.

Both indictments may be seen here.