The man who was running the Bureau of Alcohol, Tobacco, Firearms and Explosives during the botched "Fast and Furious" gun-trafficking sting has been reassigned, the U.S. Justice Department said Tuesday.

Kenneth Melson will be succeeded as acting ATF chief by B. Todd Jones, currently the U.S. attorney in Minnesota.

Melson is to become a senior adviser on forensic science in the Office of Legal Policy, the department said in a statement, which did not mention Fast and Furious or offer a reason for the personnel shakeup.

The move comes amid ongoing Justice Department and congressional investigations of the controversial 2009-2010 operation, which saw ATF agents allow weapons to be bought by straw purchasers at U.S. gun shops in a bid to trace them to powerful drug traffickers in Mexico.

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 Justice Department has acknowledged that weapons linked to Fast and Furious were found at 11 additional crime scenes in the United States, the Los Angeles Times reported earlier this month.

The admission came in a July 22 letter to the chairman and ranking member of the Senate Judiciary Committee, according to the Times.

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

Justice officials also said in the letter to Sens. Patrick Leahy (D-Vt) and Charles Grassley (R-Iowa) that Melson "likely became aware" of Fast and Furious as early as December 2009, a month after the program began.

Melson has said he did not learn about Fast and Furious until January of this year, when the U.S. government shut down the troubled operation.