Washington (CNN) -- A spokeswoman for a lawmaker leading the congressional investigation into a controversial ATF program said Friday that the Justice Department is correcting information it provided on the number of crimes in which guns tied to the "Operation Fast and Furious" program were recovered.
In a written document last month, the Justice Department told Sens. Charles Grassley, R-Iowa, and Patrick Leahy, D-Vermont, that the Bureau of Alcohol, Tobacco and Firearms "is aware of 11 instances where a recovered firearm associated with this case was recovered in connection with a crime of violence with the United States," according to Beth Levine, a spokeswoman for Grassley.
Grassley has since been informed that the information will need to be corrected, Levine said, adding that Grassley does not know whether the number will be increased or decreased, nor by how much.
The information from Assistant Attorney General Ronald Weich was provided to Grassley and Leahy on July 22 as a follow-up to Attorney General Eric Holder's appearance before the Senate Judiciary Committee in May.
The number of instances in which weapons associated with the controversial gun-purchasing program near the Mexican border were recovered is a critical point in the ongoing debate about the operation.
Operation Fast and Furious focused on following "straw purchasers," or people who legally bought weapons that were then transferred to criminals and destined for Mexico. But instead of intercepting the weapons when they switched hands, Operation Fast and Furious called for ATF agents to let the guns "walk" and wait for them to surface in Mexico, according to a report by the House Oversight and Government Reform Committee.
However, many weapons were lost in the process.
The program was shut down after guns traced to Fast and Furious were recovered following the killing of Border Patrol Agent Brian Terry in Arizona in December.
The Justice Department had no immediate response to Levine's assertion Friday that it is "backtracking" on the original figures cited in Weich's report.
The ATF has said most of the weapons were recovered from weapons tracing.
Grassley and House Oversight Committee Chairman Darrell Issa, R-California, are leading the congressional investigations into the ATF operation. More hearings on the issue are planned for the fall.
In the meantime, the Justice Department inspector general is conducting an internal investigation of the origins and execution of the operation.