EXCLUSIVE: Four congressional committees are demanding answers from the FBI and departments of Justice and Defense about a taxpayer-funded school that markets to the military, after a Fox News investigation exposed alleged ties between the university's leadership and the Chinese military.

The ongoing Fox News investigation has focused on the Virginia-based University of Management and Technology, its president Yanping Chen Frame and the school's academic dean, J. Davidson Frame, Chen's husband. UMT was raided by the FBI in 2012 as part of a counterintelligence investigation, but multiple sources told Fox News the case ran into roadblocks once it reached the U.S. attorney's office.

"There's not only a lot of smoke coming out of this one, there's some fires out there that need to be extinguished and some people that really have to answer the questions," House Oversight Committee Chairman Jason Chaffetz, R-Utah, said.

In a letter to Defense Secretary James Mattis on April 12, Chaffetz said military service members and their personnel records remain at risk. He questioned why the Defense Department continues to fund the school with taxpayer dollars through the GI Bill and the tuition assistance program.

"There was no obligation to give this money. They didn't have to give this money. Somebody made a proactive decision to authorize this, to move forward, and then why not cut it off?" Chaffetz said.

Since the 2012 FBI raid, UMT received more than $6 million. Some $250,000 has been received by the school since Fox News aired its first report in February.

"It's a bad deal for the soldiers … it's a bad deal for the taxpayer," said former UMT employee Stephen Rhoads, a U.S.-veteran-turned-whistleblower who says he worked as an FBI informant on the case. "It absolutely disgusts me and needs to stop."

After the Fox News investigation, the Defense Department put the school under review but continues to fund it. When he worked there, Rhoads said the school got more than 250,000-$300,000 per month in taxpayer dollars.

Photos obtained by Fox News apparently show Chen wearing the uniform of a young officer in the Chinese military of the People's Liberation Army, known as the PLA, along with her family. In another undated photo, Chen appears to salute the grave of her father, Chen Bin, who was a senior general in the PLA in charge of technology and arms acquisition.

"Her father joined the Communist Party in the 1930s. He supposedly participated in the Long March and that … gives her credentials not unlike being an officer in the continental army," said Peter Mattis, a fellow with the Jamestown Foundation and leading expert on China. "The Long March," between 1934-1935, has long been referred to as a bloody pillar of the Chinese Communist Revolution which ultimately led to the creation of the People's Republic of China.

Mattis said a school like UMT would be attractive to the Chinese military.

"You get what you'd call a curated database. You're not just getting a database of a lot of Americans. You're getting a database of people who are interesting to you, people who work in the U.S. military, who have access to a sensitive technology," Mattis said. "This is valuable to China for two reasons. The first is, militaries everywhere want to know what a potential adversary might look like -- what are their capabilities, how will they act? The second is this might also serve as a vehicle for recruiting individuals."

Mattis added, "If intelligence is a numbers game and maybe one out of 100 or one out of 500 people are willing to commit treason, then the faster you can go through those numbers, the better off you are. They're looking for former officials, classmates, spouses, friends and they have no problem recruiting someone with only secondhand access to information."

Fox News has confirmed that the Naval Criminal Investigative Services (NCIS) is also investigating the UMT. Separately, multiple sources told Fox News that the U.S. attorney for the Eastern District of Virginia, James P. Gillis, declined to prosecute in 2014, but that may be about to change.

The FBI, the U.S. attorney for the Eastern District of Virginia and the Defense Department declined to comment, citing the ongoing probe.

Chaffetz stressed his dismay with the reaction of the Department of Justice. "Just turning the other cheek on something that appears at least on the surface to be so blatant -- that begs the question, what are the 100,000-plus people at [the Department of Justice] doing?"

Fox News has an open invitation for an interview with Yanping Chen and J. Davidson Frame. They told Fox News in February they were too busy.