Army Sgt. 1st Class Earl D. Plumlee accepts the Silver Star for heroism in Afghanistan on May 1, 2015. He was recommended for the Medal of Honor by senior military officials in Afghanistan, but the Army approved the lower award instead. (Photo by Spec. Codie Mendenhall/ U.S. Army)

The Pentagon’s top watchdog has launched an investigation into the case of a Green Beret war hero who was recommended for the nation’s highest valor award — the Medal of Honor — by senior military officers in Afghanistan, but instead received a decoration two levels lower.

Deputy Defense Secretary Robert O. Work requested a review of Army Sgt. 1st Class Earl D. Plumlee’s case in a Sept. 2 letter to Defense Department Inspector General Jon T. Rymer. Work asked Rymer to examine the Medal of Honor nomination and the subsequent decision to award the Silver Star instead.

“In particular, I request that you examine whether there were any deviations from the standard procedures for processing such valor awards,” Work said in his letter, which was obtained by The Washington Post.

[The Army denied a Medal of Honor to this Green Beret war hero. What happened?]

The investigation comes as the Pentagon is set to release the results of a long-awaited review of its awards process, and whether service members have always been recognized appropriately for their heroism in combat. Rank-and-file troops have long questioned how much politics and personalities play a part in the process, which service officials defend as fair and impartial.

Plumlee, a member of 1st Special Forces Group and a former reconnaissance Marine, is credited with playing a leading role in stopping a fierce Taliban assault on Forward Operating Base Ghazni, a coalition installation in eastern Afghanistan. The Aug. 28, 2013, attack was launched with a 400-pound car bomb rocking the eastern side of the base, with insurgents pouring through a hole left in the wall while armed with suicide vests, a grenade launcher, hand grenades and small arms.

Plumlee was nominated for the Medal of Honor by the head of a Special Operations task force in Afghanistan, Army Col. Patrick B. Roberson, two months after the attack, according to documents obtained by The Washington Post. Senior military officers in Afghanistan at the time — including Marine Gen. Joseph F. Dunford, who will soon become the next chairman of the Joint Chiefs of Staff, and Gen. Mark A. Milley, who just became the chief of staff of the Army — signed off on the recommendation, typically the largest hurdle to receiving a major valor award.

Marine Gen. Joseph F. Dunford is shown here congratulating U.S. Army Sgt. Maj. Lester Edwards after being presented with the Bronze Star with “V” device, Sept. 15, 2013, for his actions in defending Forward Operating Base Ghazni from the Taliban the previous month. Dunford, now the commandant of the Marine Corps, recommended that Sgt. 1st Class Earl D. Plumlee receive the Medal of Honor. (Photo by U.S. Army Staff Sgt. Bryan Spreitzer/ U.S. Army)

But Plumlee’s Medal of Honor nomination was not approved once it reached the United States. Army Secretary John McHugh instead signed off on a Silver Star for Plumlee in March after a panel at Fort Knox, Ky., overseen by the Army’s Human Resources Command and known as the Senior Decorations Board, recommended that the higher award not be approved, Army officials said.

The case, detailed in a front-page story by The Washington Post in June, drew concerns from Rep. Duncan D. Hunter (R-Calif.), who questioned whether Plumlee did not receive the award because the Army’s Criminal Investigation Command (CID) had examined whether he had illegally sold a rifle scope online. That investigation yielded no charges, but Hunter questioned whether Plumlee was treated fairly.

Hunter tied Plumlee’s case to that of two other soldiers: Lt. Col. Jason Amerine, a Green Beret who is under investigation by the Army for possibly disclosing classified information about U.S. hostage policy, and Maj. Mathew L. Golsteyn, who was investigated for the alleged unlawful killing of a suspected Taliban bomb maker in Afghanistan in 2010. Neither was charged with a crime, but Amerine was removed from his job at the Pentagon in January and Golsteyn was recommended for involuntary separation from the Army in June.

[Pentagon review of how troops get recognized for combat heroism in final stages]

“Specifically, my concern is that the Army — under the leadership of Secretary of the Army — has used CID for the purpose of influencing actions/outcomes and retaliating against soldiers,” Hunter said in a May 19 letter to Rymer.

A spokesman for Hunter, Joe Kasper, said Tuesday that the inspector general’s office found in June that the Army was within its rights to launch an investigation into Plumlee’s alleged actions and notified Hunter’s office afterward. Work referenced that in a new letter to Hunter also sent Sept. 2.

“On June 26, 2015, the Office of the Inspector General responded to you regarding their investigation into the actions of the U.S. Army Criminal Investigation Command following complaints lodged against Sergeant First Class Plumlee,” Work’s letter said. “Now that the previous investigation is complete, I have asked the Inspector General to open a separate review of the circumstances surrounding Sergeant First Class Plumlee’s award in response to the allegations in your letter of May 19, 2015. ”

Polish soldiers pull security near a breach in the perimeter wall following a complex attack on Forward Operating Base Ghazni, Aug. 28, 2013. Coalition partners, with the help of the Afghan National Army, defeated the Taliban attack. (Operational photo courtesy of Polish Land Forces)

Plumlee, then a staff sergeant, rushed to the site of the car bombing near the base’s airfield in an unarmored pickup truck while under fire, including from a 30mm grenade that hit the vehicle’s front passenger-side headlight, but didn’t explode, according to a narrative of his actions provided to The Post. He exited the truck armed with a 7.62mm assault rifle, but couldn’t get it to work and swapped it for a pistol to shoot at several insurgents.

Plumlee killed one of the insurgents with a hand grenade, prompting his suicide vest to explode. Plumlee continued to fire, and suicide vests for at least two insurgents also detonated, according to the narrative. Plumlee continued to brave enemy fire to apply tourniquets to a wounded soldier, and then directed a civilian and a U.S. soldier nearby to drive the wounded to a surgical team on base.

Dunford, currently the Marine Corps commandant, described Plumlee’s actions as “truly extraordinary” in recommending the Medal of Honor. Milley and Maj. Gen. A. Scott Miller, who is now the commanding general of the U.S. Army Maneuver Center of Excellence at Fort Benning, Ga., also signed off on the nomination.

[Alwyn Cashe, the Medal of Honor and how valor gets undervalued]

Lt. Col. Jennifer Johnson, an Army spokeswoman, said Tuesday that they could not comment on the investigation. Bridget Serchak, a spokeswoman for Rymer, said that the inspector general does not confirm or deny the existence of an ongoing investigation or comment on them.

Kasper, Hunter’s spokesman, said it will fall on Rymer and Defense Secretary Ashton B. Carter to make sure that the right issues are examined in Plumlee’s case, and that the investigation doesn’t focus too narrowly on the technical details about how the Army recognizes valor, rather than the justification for denying Plumlee the Medal of Honor.

“The Army needs to say why and prove that it didn’t downgrade the award based on an investigation that didn’t determine much of anything,” Kasper said. “For Plumlee’s award, it’s going to be hard not positioning the Army against everyone else, because the Army’s logic and actions here defy common sense, and denying the award on the grounds they did is a show of disrespect to one of its top soldiers.”