Dozens of senior-level U.S. government officials turned a blind eye to public safety as they pursued an ill-conceived and poorly managed investigation into gun trafficking in Mexico, according to a long-awaited inspector general's report on Operation Fast and Furious.

Portions of the Justice Department IG report, which has not been made public, were obtained exclusively by Fox News Channel.

The report and accompanying accounts cite a failure in leadership and a lack of accountability and oversight up and down the chain of command at the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), the Justice Department itself and other offices. It says many senior executives knew the U.S. was helping traffic guns to Mexico that killed people but did nothing to stop it.

"We found no evidence in Operation Fast and Furious that the ATF or the (U.S. attorney's office) attempted at any point during the investigation to balance the risks to the public safety against the long-term benefits of identifying trafficking networks and participants," the draft report says.

Fast and Furious was the anti-gunrunning sting that helped send some 2,000 assault weapons to Mexico under the guise of stopping illegal trafficking. The operation ended only after the death of Border Patrol Agent Brian Terry -- two of the weapons associated with the investigation were found at his murder scene.

Much of the blame in the report is directed at three ATF managers: Phoenix Agent in Charge Bill Newell, Supervisor Dave Voth and Case Agent Hope MacAllister.

Their attorneys claim they've been scapegoated. Debra Roth, an attorney for MacAllister, wrote to Inspector General Michael Horowitz that the report "fails to account for the abdication of oversight, guidance and responsibility by ATF headquarters and Main Department of Justice regarding the implementation of what is in essence a strategy to combat an international criminal enterprise."

The documents obtained by Fox News, while incomplete, provide an early glimpse into the finger-pointing that will follow the expected release later this week or early next week of the complete IG report. Attorney General Eric Holder has said the report, which will be scrutinized on Capitol Hill, will provide him the basis to discipline or fire those found most culpable.

While the report blames Newell and Voth for poor judgment, attorneys for the two say higher-ups and the entire ATF chain of command were aware of everything they did.

Both men recall a detailed briefing Voth delivered to senior ATF and DOJ staff in Washington on March 5, 2010. In a Power Point presentation, attended by at least two deputy attorneys general, Voth explained how the operation was run and how almost two-dozen largely unemployed men bought 1,026 assault weapons with $650,000 in just over four months, then smuggled the guns to Mexico while under surveillance.

"Following the briefing ... Mr. Voth received accolades from his superiors. No one in ATF leadership or at Main Justice raised any concerns with Mr. Voth about the direction of the investigation. If anything, they were encouraging him," Voth attorney Joshua Levy said.

Attorneys for the three contend that the report's conclusion that the strategy for Fast and Furious was hatched in Phoenix is not true. MacAllister's attorney claims that it was "part of the overall ATF Southwest Border strategy to deal with an international criminal enterprise engaged in firearms trafficking."

Horowitz said late last week that he expects the full report to be released later this week or early next. He is currently scheduled to testify in front of the House Oversight and Government Reform Committee next Wednesday.