PHOENIX — The U.S. Justice Department denied a claim made to lawmakers that two guns sold in purchases sanctioned by federal firearms agents were later used in a shootout that left a Border Patrol agent dead near the Arizona-Mexico border.

1. More U.S. news
   1. NSA may stop vacuuming Americans' phone data

      The National Security Agency is reviewing whether to stop collecting a vast stockpile of records of Americans’ telephone calls by allowing telecommunications companies to retain the data until U.S. intelligence officials have a specific reason to review it for possible connections to terror plots.

   2. Disabled Ohio woman, daughter held captive for 2 years
   3. Bulger witness: We were 'up to our necks in murder'
   4. NSA: Surveillance thwarted NYSE, subway bombings
   5. Analysis: Why Edward Snowden isn't a 'whistle-blower'

Assistant U.S. Attorney General Ronald Weich said in a letter obtained Tuesday by The Associated Press that the claim that agents with the Bureau of Alcohol, Tobacco, Firearms and Explosives sanctioned or knowingly allowed the sale of assault weapons to straw buyers who then brought them to Mexico is false.

Such a claim was made about guns used by bandits in the Dec. 14 fatal shooting of Border Patrol agent Brian A. Terry .

"ATF makes every effort to interdict weapons that have been purchased illegally and prevent their transportation to Mexico," Weich said in a letter to U.S. Sen. Charles Grassley of Iowa.

1. Only on NBCNews.com
   1. 

      OWN via Getty Images
      From belief to betrayal: How America fell for Armstrong
   2. 

      pool via Reuters file
      US to Syria neighbors: Be ready to act on WMDs
   3. China: One-child policy is here to stay
   4. 

      NRA: Practice Range
      New 'Practice Range' shooter game says it’s from NRA
   5. 'Gifted' priest indicted in crystal meth case
   6. 

      AFP - Getty Images
      China's state media admits to air pollution crisis
   7. 

      AFP - Getty Images
      French to send 1,000 more troops to Mali

Grassley, who was examining the claim received by his fellow Senate Judiciary Committee members, had previously said that he received information that appeared to partially corroborate the claim.

Grassley spokeswoman Beth Pellett Levine said the Justice Department denied one aspect of allegations presented by whistleblowers and promised to give the senator a briefing. "However, the briefing has still not occurred, and documents provided with the allegations are not consistent with that denial," she said. "There are many specific questions that need to be answered in full by the Justice Department as soon as possible."

Terry was waiting with other agents near the Arizona border city of Nogales when a shootout with bandits erupted. Terry, who was the only person killed in the attack, was part of an elite squad similar to a police SWAT team that was sent to the canyon 13 miles north of the border known for robberies, drug smuggling and violence. No other agents were injured.

Grassley had told the Justice Department in an earlier letter that a buyer purchased three assault rifles with cash more than a year ago in the Phoenix suburb of Glendale, and two of those guns were used in the shootout that took Terry's life. His letter didn't elaborate on the possible role of federal agents in the sale of the guns, and it couldn't be determined if the purchases were part of a sting operation.

ATF spokesman Drew Wade declined to comment. Calls to the FBI office in Phoenix, which is investigating Terry's death, also weren't immediately returned Tuesday afternoon.

Grassley had previously said an ATF manager in Phoenix questioned an agent who answered questions posed by Grassley staffers about the agency's initiative to reduce the flow of firearms to Mexico — and that the manager accused the agent of misconduct for his contacts with the Judiciary Committee.

Weich said ATF made no attempt to retaliate against one of its agents and asked that the committee staffers not try to contact agents about the probe into Terry's death in an effort to protect investigators from inappropriate political influence.

Weich said the Justice Department will give Grassley a briefing about ATF's initiative to reduce the flow of firearms to Mexico, but won't address pending investigations.

U.S. firearms agents told NBC News in a December 2010 report that an estimated 80 percent of the weapons used by Mexican drug traffickers come from the United States, where cartel leaders are hiring Americans with clean records to make the purchases for them. In the past four years, Mexican authorities say they have seized 90,000 weapons from their nation's drug war.

The Associated Press contributed to this report.