The I.T. firm Hillary Clinton entrusted her email server while she was Secreary of State was never cleared to handle classified materials, according to the chief spokesman for the Defense Security Service.

The Defense Security Service (DSS) is an arm of the Defense Department and is the only federal agency authorized to approve private sector company access to sensitive or confidential material, according to the DSS website.

As stated on the website, the agency reviews and approves private contractors to verify if they have secure facilities and approves security clearances for employees so that they may have access to sensitive or classified materials.

Since 2013, Clinton used Platte River Networks, a Denver-based company, to upgrade and maintain her private email server at her home in Chappaqua, New York, whose contents were just recently leaked, as previously reported by HNGN.

About 13,000 companies were approved by the DSS to have facility-wide clearance or FCL, but Platte was not one of them.

"Platte River is not cleared" to have access to classified material, stated Cindy McGovern, chief public affairs officer for DSS in a telephone interview with The Daily Caller News Foundation.

Sen. Ron Johnson, chairman of the Senate Committee on Homeland Security and Government Affairs, told the DCNF that the Platte River involvement "raises serious questions" about the security surrounding Secretary Clinton's server over the last two years.

"The revelation that Secretary Clinton used a private company, Platte River Networks, to maintain her personal server raises questions about what steps the company took to preserve and secure sensitive information in Secretary Clinton's email," Johnson said.

Alex McGeorge, the head of threat intelligence at the IT cybersecurity firm Immunity told TheDCNF that all facilities approved for access to classified materials need a "SCIF" – or Sensitive Compartmented Information Facility – also known as a hardened room.

"It's a room that is resistant to eavesdropping and unauthorized entry limited to personnel with security clearances. That would be a room that where data coming in and out of the room is tightly controlled," he said. He went on to note that servers that contain top secret information, would need to have standards that go far beyond compartmentalized clearance to be accessed.

Platte River has not yet responded to any inquiries about this revelation.