The embattled Secretary of Veterans Affairs Eric Shinseki is facing growing pressure to resign amid reports of supposedly preventable deaths, alleged manipulation of medical waitlists and other VA failures.
Several U.S. officials as well as the American Legion, the country's largest veterans group, have called on Shinseki to quit his post. Last week, the House Committee on Veterans' Affairs voted to subpoena Shinseki, who is set to testify before the Senate Committee on Veterans' Affairs on Thursday.
The questions surrounding the VA's leadership come amid growing controversy about the department's handling and oversight of hospitals dedicated to caring for the nation's veterans. Various congressional and government investigations of the agency have been conducted. The results of those investigations have suggested lapses in operational control at some facilities and problems with communication and oversight within the agency. (CNBC conducted its own investigation as well).
Multiple sources, including Rep. Jeff Miller, R-Fla., chairman of the House Committee on Veterans' Affairs, told CNBC they believe lower-level bureaucrats within the department are keeping certain damning reports from the secretary.
"Unfortunately, part of the problem is there is a midlevel bureaucracy within VA that will not give the secretary the information that he needs to do his job," Miller told CNBC in an interview in November.
"It's a system management problem," he said.
Take the response one whistle blower, who worked with the U.S. Office of Special Counsel on two investigations of the VA, got from a director at the agency's headquarters when queried about whether Shinseki had been informed about patient care issues.
"He told me 'we don't bother him (Shinseki) with these things; we only tell him the good news'," the source told CNBC on the condition of anonymity.
That source worked for eight years at the Jackson VA in Mississippi and the VA in Gainesville, Florida, the largest in the country.
But problems with the agency's hospital oversight have weighed on the department's leadership. So much so that some—VA headquarters sources, former VA employees and congressional sources who spoke to CNBC anonymously for fear of their jobs—believe Shinseki tried to tender his resignation at least once last year, but was rebuffed by President Obama.
CNBC was unable to confirm those claims, and the White House declined to give any comment.
The Department of Veterans Affairs, denied that Shinseki ever tried to quit and defended the secretary's job performance.
"As he always says, 'I serve at the pleasure of the president. I signed on to make some changes, I have work to do,'" VA spokesman Drew Brookie wrote in an email to CNBC.
Brookie added that under the leadership of Shinseki and his team, the agency has made strong progress in recent years to better serve veterans.
The agency has repeatedly stated in recent months that it takes reports of poor patient care seriously and has vowed swift action should allegations against the agency prove true.
CNBC first reported on issues within the VA Healthcare System last August, culminating in a documentary "Death & Dishonor: Crisis at the VA" that was released last year.
The Department of Veterans Affairs is the second-largest federal agency, with a proposed 2015 budget of over $163 billion; a nearly 6.5 percent increase above 2014 funding levels of over $152 billion.
It is the largest integrated health-care system in the country with over 1,700 hospitals, clinics, community centers and other facilities.
In CNBC's documentary, Miller said, "If we were to have to go to other missions, somewhere around the world, I don't know if VA can handle it. And my concern is they always want to keep it inside the four walls of the Veterans Affairs."
—By CNBC's Dina Gusovsky.