Army Col. Mark Fassl, the former military inspector general for the U.S. and coalition training command in Afghanistan, was told at the time to abandon his inquiry into the appalling conditions and reports of corruption at the Dawood National Military Hospital in Afghanistan.
While funded in part by U.S. dollars, the hospital was operated by the Afghan ministry of defense and interior.
Caldwell, who now heads U.S. Army North Command, was "visibly upset" over the Dawood investigation and his request for support from the Pentagon on the inquiry, Fassl told House members.
The three-star general questioned the timing of the investigation, its proximity to the 2010 congressional midterm elections and the potential blowback from the White House, during a conversation with Fassl.
"He calls me Bill," Fassl said, recalling Caldwell's comment during their conversation indicating the three-star general's close relationship with President Obama.
The investigation was eventually closed under Caldwell's orders, despite the "very abusive and corrosive ... situation that was ongoing and getting worse," at the hospital, Fassl said.
That situation included the families of patients changing bandages and doing other basic medical tasks instead of the doctors and nurses on staff at the hospital, Fassl said.
Blood from patient's wounds were draining into open vats on the hospital floor, while the floor itself was littered with blood and human feces, he added.
Fassl's account of the Dawood investigation drew the ire of panel chairman Jason ChaffetzJason ChaffetzHow Chaffetz could get rich on K Street Oversight asks Trump for details on foreign profit donations Jason Chaffetz exploring private sector jobs: report MORE (R-Utah) and ranking member Rep. John Tierney (D-Mass.)
Caldwell's decision to scuttle the investigation "to promote the goodness that's going on [in Afghanistan] ... is totally unacceptable," Chaffetz said.
"Were we purposely blind because we didn't want to rock the boat" with the White House and the Afghan government? Tierney asked. "We didn't set this up right from the get-go."
The Utah Republican wrote a letter in June to Defense Secretary Leon Panetta, publicly accusing Pentagon officials of delaying a military investigation into the hospital until after the 2010 midterm elections to protect Obama from bad publicity.
Department of Defense spokesman George Little told reporters on Tuesday that the Pentagon's Inspector General was looking into the circumstances that led to Caldwell's decision regarding the hospital.
While declining to go into specifics regarding the ongoing DOD IG inquiry into Dawood, Little did say "corrective measures" have been taken to improve the level of care at the hospital.