The U.S. Justice Department has acknowledged that weapons linked to the botched "Fast and Furious" gun-trafficking sting were found at 11 additional crime scenes in the United States, the Los Angeles Times reported.

The revelations "vastly broaden the scope of the danger" arising from the Bureau of Alcohol, Tobacco, Firearms and Explosives' controversial 2009-2010 operation, under which agents allowed weapons to be bought by straw purchasers at U.S. gun shops in a bid to trace them to powerful drug traffickers in Mexico.

But once Fast and Furious got under way, ATF agents realized they had no dependable way to keep track of the guns, which eventually began appearing at crime scenes on both sides of the border.

The failure of the undercover operation, in which other federal government agencies also participated, has caused friction in U.S.-Mexican relations and is the subject of separate investigations by the U.S. Justice Department and Congress.

According to the daily, the Justice Department acknowledged in a July 22 letter to the Senate Judiciary Committee that weapons linked to Fast and Furious were found at 11 additional crime scenes in the United States.

Two semi-automatics had previously been discovered after the slaying last year of a U.S. Border Patrol agent in southern Arizona.

Although the Justice Department did not provide details on those 11 additional scenes in the letter, the Times said it learned the crimes occurred in Phoenix - where ATF managed Fast and Furious - and other Arizona cities, as well as in in Texas, where authorities recovered 42 Fast and Furious weapons.

Citing an anonymous source close to the investigation, the daily said the weapons appeared at crime scenes in the Arizona cities of Phoenix, Nogales, Douglas and Glendale and in El Paso, Texas.

Justice officials also said in the letter to Sen. Patrick Leahy (D-VT) and Sen. Charles Grassley (R-IA), the leading members of the Senate Judiciary Committee, that the ATF's acting director, Kenneth E. Melson, "likely became aware" of Fast and Furious as early as December 2009, a month after the program began.

Melson, who has come under heavy criticism from Congress, has said he did not learn about Fast and Furious until January of this year, when the U.S. government canceled the botched operation.

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