WASHINGTON -- Like other U.S. trainers with the Afghan force that day, former Army Capt. William Swenson had expected light resistance. Instead, the contingent walked into a furious six-hour gunfight with Taliban ambushers in which Swenson repeatedly charged through intense fire to retrieve wounded and dead.

The 2009 battle of Ganjgal is perhaps the most remarkable of the Afghan war for its extraordinary heroism and deadly incompetence. It produced dozens of casualties, career-killing reprimands and a slew of commendations for valor. They included two Medal of Honor nominations, one for Swenson.

Yet months after the first living Army officer in some 40 years was put in for the nation’s highest military award for gallantry, his nomination vanished into a bureaucratic black hole. The U.S. military in Afghanistan said an investigation had found that it was “lost” in the approval process, something that several experts dismissed as improbable, saying that hasn’t happened since the awards system was computerized in the mid-1970s.

In fact, the investigation uncovered evidence that suggests a far more troubling explanation. It showed that as former Marine Cpl. Dakota Meyer’s Medal of Honor nomination from the same battle sailed toward approval despite questions about the accuracy of the account of his deeds, there may have been an effort to kill Swenson’s nomination.

Swenson’s original nomination was downgraded to a lesser award, in violation of Army and Defense Department regulations, evidence uncovered by the investigation showed.

Moreover, Swenson’s Medal of Honor nomination “packet,” a digitized file that contains dozens of documents attesting to his “heroism . . . above and beyond the call of duty,” disappeared from the computer system dedicated to processing awards, a circumstance for which the military said it has “no explanation.”

The unpublished findings, which McClatchy has reviewed, threaten to taint a military awards process that’s designed to leave no margin of doubt or possibility of error about the heroism and sacrifices of U.S. service personnel. They also could bolster charges by some officers, lawmakers, veterans’ groups and experts that the process is vulnerable to improper interference and manipulation, embarrassing the military services and the Obama administration.

“The whole awards system is just totally jacked up,” said Doug Sterner, a military historian who’s made a career of verifying the authenticity of commendations.

The Pentagon and the military services deny that the system is flawed, and the U.S. command in Afghanistan denied that there was any attempt to downgrade Swenson’s Medal of Honor nomination.

Yet despite the possibility of malfeasance or worse, no further effort was made to determine what happened. The “discrepancies” posed by the evidence of a downgrade to a Distinguished Service Cross “could not be resolved,” the investigators said.

Swenson’s nomination was resubmitted last year. President Barack Obama must approve it before Sept. 8, the third anniversary of the battle, or it expires and can only be revived by an act of Congress.

It couldn’t be determined whether there was an effort to kill Swenson’s Medal of Honor nomination, but there are several possible motives for doing so.