An unnamed “senior aide” to then-Secretary of State Hillary Clinton left classified information unsecured and unattended in a hotel room during a 2010 trip to China, one of several overseas lapses by Clinton’s inner circle, Fox News has learned.

Confirmation of the alarming violation comes as Clinton herself is under a renewed FBI probe for mishandling sensitive information on a private server and her longtime senior aide, Huma Abedin, also faces scrutiny as part of the investigation. It was not known which of Clinton’s aides left the information exposed.

“In May 2010, Secretary Clinton was on official travel in Beijing, China, accompanied by senior staff. Upon Secretary Clinton’s departure, a routine security sweep by Diplomatic Security agents identified classified documents in a staff member’s suite,” State Department spokesman John Kirby told Fox News in a statement, issued several weeks after a Freedom of Information Act request was filed with the agency.

Diplomatic Security, which protects the Secretary of State in the U.S. and abroad, as well as high-ranking foreign dignitaries and officials visiting the United States, wrote up the incident on a Form 117, while the Marine Security Guards filed a separate formal report, the source said.

The information came to light when the FBI was investigating whether Clinton or her staff violated the US Espionage Act by mishandling classified and top secret information.

House Permanent Select Committee on Intelligence Chairman Devin Nunes, R-Calif., citing a whistleblower who separately came to him with an allegation it was Clinton who left the material out, wrote to the FBI director on Monday asking for more information.

“I …understand that former Secretary Clinton left classified documents in her hotel room in China and that U.S. Marine Corps security officials filed a report related to the possible compromise of the documents,” Nunes wrote to FBI director James Comey.

Additionally, Nunes said an email released in response to a FOIA request described Abedin asking another staffer to remove “burnstuff” Abedin had left in a car during a trip to India.

Kirby told Fox News that incident may not have involved classified material.

“This email exchange does not show that classified information was left in a motorcade car,” Kirby said of that incident. “Sensitive But Unclassified material is routinely disposed of in burn bags. As the regulations state, Sensitive But Unclassified (SBU) and Personally identifiable information (PII) documents are often burned. So it’s not accurate that any reference to a document going to a burn bag is a document that includes classified material.”

As for the China incident, Kirby insisted that Clinton had nothing to do with the matter.

“To be clear – this was not Secretary Clinton’s hotel room and no citation whatsoever was given to Secretary Clinton, nor were any reports written about Secretary Clinton’s conduct,” Kirby said in the statement.

At the time of the security sweep, the suite was still inside of a Diplomatic Security-controlled area, Kirby said, and under the direct control of a Diplomatic Security agent posted outside the room.

“Ultimately, Diplomatic Security concluded that classified information had been improperly secured, but that the evidence did not support assigning culpability to any individual. Furthermore, the Diplomatic Security investigation concluded that due to the fact that the documents were found within a Diplomatic Security controlled area, the likelihood that the information was compromised was remote.”

Leaving out classified or top secret information is a serious offense, a former state department staffer told FoxNews.com.

“Diplomatic Security and the Marine Security Guard takes exposure of classified information very seriously,” said Jessica Vaughan, director of policy research at the Center for Immigration Studies. “You can lose your security clearance if you’re caught more than once, and that means you might lose your job. It’s a big deal.”

As FoxNews.com reported Sept. 30, a top aide to then-Secretary of State Hillary Clinton found herself in hot water in 2013 with the agency’s security and law enforcement arm when she lost classified information while accompanying her boss on a diplomatic trip to Moscow, an incident that the FBI also revisited earlier this year when it probed Clinton’s own problems handling sensitive data.

Monica Hanley, Clinton’s “confidential assistant” at the state department, was reprimanded and given “verbal counseling” by Diplomatic Security after she left classified material behind in the Moscow hotel, FBI documents show. The FBI spoke to Hanley, 35, in January as a part of its investigation into Clinton’s handling of top-secret and classified information when she was Secretary of State.

During her trip with Clinton to Russia, Hanley was given a “diplomatic pouch” that held Clinton’s briefing book and schedule for her Russian trip. Hanley brought the pouch and its contents into the Russian hotel suite, which she shared with Clinton, but she left behind some of those classified documents, the FBI report revealed.

Diplomatic Security found the classified document in that suite during a routine sweep after Clinton and Hanley left the hotel. Agents subsequently informed Hanley “the briefing book and document should never have been in the suite.”