Senior defense officials suppressed a study documenting $125 billion worth of administrative waste at the Pentagon out of fears that Congress would use its findings to cut the defense budget, The Washington Post reported late Monday.

The report, which was issued in January 2015 by the advisory Defense Business Board (DBB), called for a series of reforms that would have saved the department $125 billion over the next five years.

Among its other findings, the report showed that the Defense Department was paying just over 1 million contractors, civilian employees and uniformed personnel to fill back-office jobs. That number nearly matches the amount of active-duty troops -- 1.3 million, the lowest since 1940.

The Post reported that some Pentagon leaders feared the study's findings would undermine their claims that years of budget sequestration had left the military short of money. In response, they imposed security restrictions on information used in the study and even pulled a summary report from a Pentagon website.

"They're all complaining that they don't have any money," former DBB chairman Robert Stein told the Post. "We proposed a way to save a ton of money."

Deputy Defense Secretary Robert Work, who originally ordered the study, told the paper that the plan laid out in the report was "unrealistic."

"There is this meme that we're some bloated, giant organization," Work said. "Although there is a little bit of truth in that ... I think it vastly overstates what's really going on."

Pentagon spokesman Peter Cook echoed Work's claim in a statement to Fox News, which said that the DBB report "had limited value" because it "lacked specific, actionable recommendations appropriate to the department."

Work claimed that some of the report's recommendations were being implemented on a smaller scale and would save an estimated $30 billion by 2020. However, the Post reported that most of the programs had been long-planned or were unrelated to the Defense Business Board report.

-- Fox News' Lucas Tomlinson contributed to this report.