The House Oversight and Government Reform Committee will hear testimony from six current and former Alcohol Tobacco and Firearms agents regarding the bureau’s botched “Fast and Furious” operation. The hearing will focus specifically on the effect the operation had in Mexico.

Operation Fast and Furious involved the sale of thousands of firearms to straw buyers, who then brought those weapons into Mexico where they were sold to criminal organizations. The operation has set off a firestorm of controversy, and the Oversight Committee has been at the forefront of investigations into which Justice Department officials knew about the program, and when.

The committee previewed the hearing in a statement on its website:

Tuesday’s hearing of the House Committee on Oversight and Government Reform will examine the effects of the Bureau of Alcohol, Tobacco, and Firearms (ATF) program dubbed “Operation Fast and Furious.”  Specifically, we will review the impact of this program on our neighbor to the south, on our agents working in, and on the people of Mexico.

The Committee’s task today is serious, and the Administration’s effort to impede this investigation slows our work to make public the truth of an acknowledged—and failed—operation.  The Acting Director of the ATF, in a transcribed interview with investigators, has said that the Justice Department is trying to push all of this away from its political appointees.  That is not the response this Committee, Congress and the public, should expect from the ‘most transparent Administration in history.’

In this hearing, lawmakers will hear firsthand from field agents who have worked in Mexico for years and who were systematically kept in the dark by officials in Phoenix and at headquarters about the real nature and scope of “Operation Fast and Furious.”  The Committee will also hear testimony from ATF supervisors who chose to allow weapons to flow from illegal sales in the United States directly into the hands of Mexican drug cartels—without interception or interdiction.

Two recent developments in the Operation Fast and Furious investigation are also likely to get some attention at the hearing.

Chairman Darrell Issa (R-CA) released a report Tuesday revealing that of the 1,418 firearms sold to straw buyers through the Fast and Furious operation, 1,048 are currently unaccounted for. The Wall Street Journal reported on Tuesday:

Federal agents running an Arizona gun-trafficking investigation can’t account for more than 1,000 firearms bought by suspected smugglers, a new congressional report said.

The report by Republican lawmakers comes ahead of a House hearing Tuesday examining tactics used by the Bureau of Alcohol, Tobacco, Firearms and Explosives in its now-controversial gun probe in 2009 and 2010.

The ATF probe was called Operation Fast and Furious and aimed to help make a big case against top smugglers who funnel weapons from the U.S. to drug-cartel gangs in Mexico.

GOP lawmakers are leading an examination of Fast and Furious, which they argue was a reckless operation because the ATF should have known it couldn’t keep track of the firearms it allowed suspects to buy.

Suspected smugglers bought 1,418 firearms after coming to the attention of ATF agents running the probe, according to the congressional report, detailing the most complete accounting to date of weapons in the operation. Of those, 1,048 haven’t been recovered or traced, the report said.

Fox News reported another twist in the scandal on Monday, suggesting that FBI agents knew that more than 300 weapons were being sold to a pair of straw buyers who were also convicted felons. The report threatens to involve even more of the Justice Department in the scandal.

In the latest chapter of the gunrunning scandal known as Operation Fast and Furious, federal officials are refusing to explain how two suspects obtained more than 360 weapons despite criminal records that should have prevented them from buying even one gun.

Under current federal law, people with felony convictions are not permitted to buy weapons, and those with felony arrests are typically flagged while the FBI conducts a thorough background check.

However, according to court records reviewed by Fox News, two of the 20 defendants indicted in the Fast and Furious investigation have felony convictions and criminal backgrounds that experts say, at the very least, should have delayed them buying a single firearm. Instead, the duo bought dozens of guns on multiple occasions while federal officials watched on closed-circuit cameras.

Congressional and law-enforcement sources say the situation suggests the FBI, which operates the National Instant Criminal Background Check System, knowingly allowed the purchases to go forward after consulting with the Bureau of Alcohol, Tobacco, Firearms and Explosives, which initiated Operation Fast and Furious. Under the failed anti-gun trafficking program, straw buyers — those who legally purchase guns and illegally sell them to a third party — were allowed to buy guns, many of which were sold to Mexican drug cartel members.

All of these issues will likely get some attention today. Scribe will be reporting from the Hill on the Oversight hearing.