"We need answers on this. Not defensive BS. Real answers."

In email exchanges with subordinates in February and March 2011, Attorney General Eric Holder and the department's second-highest official expressed growing concern that something might have gone wrong in a federal gun-smuggling probe called Operation Fast and Furious.

Two of Holder's emails and one by Deputy Attorney General James Cole were among documents the Justice Department showed Tuesday to Republican and Democratic staffers of the House Oversight and Government Affairs Committee in an effort to ward off a criminal contempt vote against the attorney general.

The full contents of the emails were described to The Associated Press by two people who have seen them. Both people spoke on condition of anonymity because they were not authorized to speak about them publicly.

For the past year and a half, some Republicans have promoted the idea that Holder and other top-level officials at the Justice Department knew federal agents in Operation Fast and Furious had engaged in a risky tactic known as "gun-walking."

Two of Holder's emails and one from Cole appear to show that they hadn't known about gun-walking but were determined to find out whether the allegations were true.

When relying on the technique of gun-walking, federal agents tried to track suspected illicit gun-buyers instead of arresting them. The hope was that the low-level "straw" purchasers would lead law enforcement to major arms-traffickers, enabling the agents to dismantle networks that had put tens of thousands of guns into the hands of Mexican drug cartels. In Operation Fast and Furious, the tracking effort failed. The operation identified over 2,000 illicitly purchased weapons. Some 1,400 of them have yet to be recovered.

The emails by Holder and Cole followed a hurried assurance by the Justice Department on Feb. 4, 2011, to Sen. Chuck Grassley, the senior Republican on the Senate Judiciary Committee. No such tactic was used, the Justice Department said in a letter to Grassley. The U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives "makes every effort to interdict weapons that have been purchased illegally and prevent their transportation to Mexico," the letter added. The letter was based on incorrect assurances supplied to the Justice Department by the U.S. Attorney's office in Phoenix and by ATF officials. The department withdrew the Feb. 4 letter on Dec. 2, 2011, after documenting what had taken place not only in Operation Fast and Furious, but in three other gun-walking operations going back to 2006.

At the Justice Department on Thursday, spokeswoman Nanda Chitre declined to comment about the e-mails.

After the Feb. 4 letter to Grassley, news stories appeared containing allegations of gun-walking. The Justice Department was awash in conflicting opinions over whether the media accounts were correct.

CBS News ran a story on Feb. 23, 2011. On March 3, CBS followed up, and the nonprofit Center for Public Integrity weighed in with its own online account.

On Feb. 23, aides passed along to the attorney general the CBS story alleging gun-walking, and the attorney general shot back, "We need answers on this. Not defensive BS. Real answers."

Five days later, Holder asked the Justice Department's inspector general to investigate.

On March 3, Cole, the No. 2 official at the Justice Department, emailed his staff: "We obviously need to get to the bottom of this."

Holder was skeptical of any assurances.

"I hope the AG understands that we did not allow guns to walk," an official at the ATF's Washington headquarters said on March 10 in an email that Holder's aides forwarded to the attorney general.

In a response, Holder wrote, "Do they really, really know" that there was no gun-walking?

A day earlier, at Holder's instruction, the Justice Department had sent out a directive to the field reinforcing a longtime Justice Department policy against gun-walking. The directive said that agents must not allow guns to cross the border into Mexico.