Swenson’s draft citation – a copy of which was obtained by McClatchy – praised him for “extraordinary heroism, exceptional leadership amidst chaos and death, and selflessness above and beyond the call of duty.”

Evidence gathered by the investigation into what happened to his original Medal of Honor nomination was detailed in documents appended to an Aug. 11, 2011, letter signed by Army Col. James H. Chevallier III, who served as a senior staff officer with U.S. forces in Afghanistan.

McClatchy was shown the letter and the attachments, and was allowed to take notes. Army Col. Thomas Collins, a Kabul-based spokesman for the International Security Assistance Force, the U.S.-led coalition of foreign troops in Afghanistan, confirmed the documents’ authenticity.Chevallier’s letter said the investigation had determined that Swenson’s nomination wasn’t “staffed to completion” and was “lost” in part because of a high staff turnover rate.

“The investigation didn’t find any evidence of criminal wrongdoing or evidence that anyone downgraded the nomination, but there were failures at multiple levels in tracking and processing the award,” Collins said in an email. “That can’t excuse what happened, and we have made adjustments to prevent it from happening again.”

But Collins’ statement and Chevallier’s conclusions don’t account for the evidence of a downgrade that’s outlined in the documents attached to the letter. The letter characterized the attachments as “a more detailed account of the award submission.”

The attachments describe PowerPoint briefing slides that staff officers routinely maintain to keep their commanders updated on the status of award nominations from their operations areas.

The slides came from the 82nd Airborne Division task force that oversaw U.S. operations in eastern Afghanistan at the time the Ganjgal battle took place and from its replacement unit, CJTF-101, from the 101st Airborne Division, which arrived in June 2010.

The attachments showed that Army Lt. Col. Fredrick O’Donnell filed Swenson’s Medal of Honor nomination electronically on Dec. 18, 2009. A May 20, 2010, slide showed the file reaching U.S. Forces-Afghanistan, the Kabul-based headquarters of the U.S. contingent within the international military coalition, a day earlier. The coalition’s commander also heads USFOR-A.

A footnote on an Aug. 21 slide said that Swenson’s nomination then was “downgraded to DSC (Distinguished Service Cross),” but that the lesser award couldn’t be conferred because “USFOR-A is currently out of certificates, but will process and return to CJ1 (a staff officer) ASAP.” A note written by the investigating officer said that the downgrade “appears to be an error as USFOR-A does not have the authority to downgrade a MoH.”

An Aug. 28 slide showed that the lower award then was sent to U.S. Central Command, in Tampa, Fla., for approval. Swenson’s Medal of Honor nomination, the slide said, was “downgraded to DSC and was forwarded to CENTCOM.”

No traces of Swenson’s Medal of Honor packet “or any other award” were found on any military computers save for an “incomplete” Medal of Honor file recovered from SIPRNET, the classified system from which the so-called WikiLeaks documents were downloaded, the attachments said.

Asked why the original packet had disappeared from the computer system dedicated for awards, Collins replied, “I have no explanation for that.”

The period in which the slides showed the downgrade taking place correspond with the second month of now-retired Army Gen. David Petraeus’s stint as ISAF commander. He is now the CIA director.

However, Petraeus, who by regulation was required to recommend approval or disapproval of the nomination, told McClatchy last week that he “has no recollection of seeing this packet.”

Army and Defense Department regulations limit commanders to three options: recommending approval, disapproval or disapproval with a downgrade to a lower award. Once a recommendation is made, the nomination must be forwarded up the command chain until it reaches the secretary of defense and the president, who has the sole authority to approve or downgrade it.

“Nominations for the Medal of Honor are considered so special and so exceptional that the nominating process is controlled by a Defense Department directive and not the services,” said Fredric Borch, a retired Army colonel and an expert on U.S. military decorations.

Several experts dismissed the notion that a Medal of Honor packet could be lost once filed in the Army’s computerized awards system.

“Assuming the nomination was entered into the system, it seems improbable to me that it disappeared,” Borch said.

The services devote enormous energy and attention to shepherding Medal of Honor nominations to approval, especially given the rarity with which the medals have been awarded in Iraq and Afghanistan, experts said. Ten have been conferred, only three of them to living recipients, prompting congressional hearings on complaints from lawmakers, military commanders and veterans’ groups that the requirements have been quietly tightened, a charge the Pentagon denies.

Moreover, the experts said, unofficial word rapidly travels to the top of the military when a Medal of Honor recommendation is made, and service leaders closely track its progress up the command chain.

Sterner said an improper downgrade could be ordered only at a senior level. “When you are dealing with a packet like this, it’s a high priority, high profile,” he said. “You are not going to have a low-level clerk with either the authority or the temerity” to make that decision.

An 82nd Airborne staff officer contacted by investigators had no recollection of handling Swenson’s nomination or briefing her 101st Airborne successor, the letter attachments said.

The attachments contained no conclusions that the file was lost because of staffing turnovers. Instead, the investigators said that “The discrepancies between the information on the slides and the actual status of the award could not be resolved.”

In resubmitting Swenson’s nomination, Allen may have created new complications.

By approving the nomination, Obama could create conflicting Marine and Army accounts of the battle, fueling questions about what supposedly is a rigorous Medal of Honor approval process.

Moreover, Swenson’s packet must be accompanied by a “timeline detailing specific processing dates for the MoH recommendation,” according to Pentagon rules. That means including the evidence of an improper downgrade.