BRASILIA (Reuters) - Brazil’s government is seeking the extradition of a Brazilian man who was arrested by U.S. authorities in Florida, allegedly for shipping automatic weapons to the South American country.

The arrest of Frederik Barbieri came one week after Brazil resorted to the military to try to control violence and crime in Rio de Janeiro, where heavily-armed drug gangs control the city’s slums.

The United States is the largest source of guns entering Brazil that end up in the hands of armed criminals and drug traffickers, according to a Brazilian police report seen by Reuters last month.

Barbieri was arrested on Friday evening at his home in Fort Pierce, Florida, Nestor Yglesias, spokesman for Immigration and Customs Enforcement’s Miami Field Office, said on Saturday.

“He was arrested by special agents from Homeland Security Investigation, which is a component in ICE,” Yglesias said, adding Barbieri will make an initial appearance before a federal magistrate on Monday.

A Brazilian law enforcement officer had earlier said Barbieri was arrested in Miami.

Brazil has sought his arrest since 60 automatic rifles, including AK-47s and other combat rifles, were found at Rio de Janeiro airport in June hidden in a shipment of pool heaters.

Barbieri denied involvement in gun running at that time, but Brazilian police have suspected his involvement since a container of ammunition was found in his name in 2010 at the port of Salvador in northeastern Brazil.

Fabricio Oliveira, head of the Federal Police’s disarmament unit in Rio, told reporters that Barbieri was arrested by U.S. Immigration and Customs Enforcement who seized 40 automatic weapons at his home.

Brazil’s Ministry of Justice said it has already asked for his extradition and is waiting for a Brazilian court to approve additional documents requested by U.S. authorities.

Barbieri moved to Florida in 2012 and obtained U.S. citizenship, which could rule out his extradition and lead to his prosecution in the United States.

“The US continues to be the largest indirect source of illegal handguns and assault rifles as a result of unrestricted sales in stores and fairs in American cities,” the Brazilian Federal Police report seen by Reuters said.

The December 2017 report said a study of more than 10,000 arms seized by police in Brazil since 2014, mostly in Rio de Janeiro, found that roughly 1,500 guns originated in the United States. The guns often traveled through a third country before arriving in Brazil, with Paraguay being the top intermediary.

Guns from the United States tended to be assault rifles and higher caliber handguns, while guns already circulating in Brazil or arriving from other countries were smaller handguns.

Eight foreign stores were named selling the most high caliber guns that ended up in Brazil, with five located in Florida, although a store in Paraguay was the largest individual seller, the report said.