Two employees for the tech firm that managed Hillary Clinton’s private email server invoked their Fifth Amendment rights in a House hearing on Tuesday.

Paul Combetta and Bill Thornton both appeared in front of the House Oversight and Government Reform Committee for a hearing to examine the preservation of Clinton’s State Department emails.

Both technicians work for Platte River Networks (PRN), a Denver-based tech firm that Clinton hired in 2013 to manage her private email setup.

Combetta is one of two technicians who was granted immunity by the Justice Department in order to cooperate with the FBI’s investigation into Clinton’s server. The other is Bryan Pagliano, a former Clinton campaign official who managed Clinton’s off-the-books email server as an IT adviser at the State Department. He ignored the Oversight Committee’s subpoena to appear on Tuesday. (RELATED: Tech Firm Charged Clinton $250 An Hour For Interviews With Feds)

Combetta’s immunity agreement has angered some Republican lawmakers because he seemingly lied to the FBI during one of two interviews he attended earlier this year.

According to the FBI’s report of its Clinton email investigation, Combetta gave conflicting answers when asked about his decision to use a software program called BleachBit to delete backups of Clinton’s emails from PRN’s servers.

During Tuesday’s hearing, Utah Rep. Jason Chaffetz, who chairs the Oversight Committee, asked Combetta whether he was involved in an Aug. 19, 2015 email chain in which a PRN employee said, seemingly in reference to the Clinton email fiasco, that they were “starting to think this whole thing really is covering up some shaddy [sic] shit.” (RELATED: Employees At Hillary’s IT Firm Were Worried They Were Covering Up ‘Shady Sh*t’)

Combetta did not answer the question and pleaded the Fifth. He also did not answer Chaffetz’s question regarding who told him to delete Clinton’s email backups.

The deletion occurred on March 31, 2015, weeks after Clinton’s private email system was first reported and after Congress had subpoenaed all of Clinton’s email records.

Combetta had talked to staffers working for Bill Clinton on March 25. He spoke to Hillary Clinton’s lawyers on March 31, just after he seemingly used BleachBit to delete her emails.

According to the FBI’s report of its investigation, Combetta refused to discuss his conversation with Clinton’s lawyers during the FBI interview, citing attorney-client privilege.

The FBI report states that the investigation “identified a PRN work ticket, which referenced a conference call among PRN, Kendall and Mills on March, 31, 2015. PRN’s attorney advised [Combetta] not to comment on the conversation with Kendall based upon the assertion of the attorney-client privilege.”

It is unclear why Combetta would have invoked attorney-client privilege, especially after having been granted immunity by the Justice Department.

But there is some evidence to suggest that Combetta’s actions were undersigned by Clinton associates.

His name appears on a Sept. 16, 2015 invoice PRN reportedly submitted to Marcum, LLC., an accounting firm that worked for the Clintons.

The invoice, which was first obtained by the website Complete Colorado, shows that PRN billed Clinton for a variety of expenses, including travel expenses and parking expenses.

The invoice also includes a $3,000 charge for “federal interviews,” suggesting that PRN sought payment for Combetta’s interviews with federal investigators. The date of the line item is Sept. 15, 2015. It is still unclear if Clinton paid PRN’s bill.

The invoice also shows that PRN charged Clinton $250 for a one-hour phone call Combetta had with an individual named Ken.

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