Investigators on the Benghazi Select Committee had hoped to question former Clinton IT specialist Bryan Pagliano over the possible destruction of evidence, known in legal circles as “spoliation,” a congressional source told Fox News.

However, in an August 31 letter to Congress, Pagliano’s attorney said the former 2008 campaign staffer who installed and managed Clinton’s personal server and left his IT job at the State Department in February 2013, the same month Clinton stepped down as secretary, would “respectfully assert his Fifth Amendment right” before the Benghazi Select Committee.

“The matters for which Mr. Pagliano’s testimony and documents are being sought by the Select Committee are also the subject of investigative activity by the Federal Bureau of Investigation and the Department of Justice,” the letter said.

According to the 2014 Black’s Law Dictionary, spoliation is “the intentional destruction, mutilation, alteration, or concealment of evidence…If proved, spoliation may be used to establish that the evidence was unfavorable to the party responsible. Also termed ‘spoliation of evidence.’”

While it is not known exactly when or who “wiped” Clinton’s personal server, it seems the move came after October 2014,when the State Department requested personal emails be returned as part of her business records.

On his Linked-In account, Pagliano said he served as “strategic advisor and special projects manager” for “a geographically diverse customer base of over 50,000 users around the world” from May 2009 - February 2013.

Committee Republicans have long argued they do not have all the documents that should be available to the investigation, after Clinton, using her personal discretion, purged some 30,000.

Former Clinton policy aide Jake Sullivan, who testified Friday before the Benghazi Committee, has direct knowledge of the policy decisions that established a U.S. consulate in eastern Libya with substandard security that did not meet State Department requirements, as well as direct knowledge of the 2012 attack  there and the administration's response. 

The Benghazi emails released in May to Congress contained only130 references to Sullivan in an online search, yet the most recent records released Monday contained more than 1,300.

Fox News put additional questions to Pagliano’s attorney, Mark J. MacDougall, Friday about whether his client played a direct role or had knowledge of the server scrub, but MacDougall said there was nothing further to add beyond the letter.

An intelligence source who confirmed to Fox that the FBI’s “A-team” was handling the Clinton email case, described the investigation as “moving along well,” adding investigators remain “confident” deleted records can be recovered because whoever did the scrub may “not be a very good IT guy. There are different standards to scrub when you do it for government vs. commercial.”

The disparities seem difficult to reconcile, also given the most iconic image of Clinton on her blackberry aboard a C-17 military plane  was during a 2011 trip to Libya, but the Select Committee said no records were provided from this period.