It's not known specifically what the documents included, but they have since been turned over to the Attorney General's Office, the source said.
Nils Frederiksen, a spokesman for the attorney general, declined comment, citing the ongoing investigation into child sex-abuse charges against former assistant football coach Jerry Sandusky, who is scheduled to go on trial in June.
Penn State officials repeatedly have told employees they were required to turn over any documents that pertained to employees or former employees involved in the case, sources said.
It is not clear why Sherburne had the Curley documents. But the source said there was no indication he had "intent" to conceal them. If he had, it could have resulted in an obstruction-of-justice charge.
Sherburne had been warned previously for trying to get rid of documents that he thought did not pertain to the case, the source said.
Both head football coach Joe Paterno, who died in January, and President Graham B. Spanier were let go in the aftermath of grand jury charges against Sandusky.
Curley and Gary Schultz, a former senior vice president, were charged with perjury concerning a 2002 incident in which a graduate assistant coach reported seeing Sandusky sexually assaulting a boy in a campus shower.
While Curley, a protégé of Paterno's, was placed on leave, Schultz decided to retire.
Both Curley and Schultz have entered not-guilty pleas to charges of perjury and failure to report. They are next due in court June 1.
Sherburne, 44, played on Penn State's baseball and football teams, according to the school's website.
A native of State College, he graduated with a bachelor of science degree in business logistics in 1991. He has held various positions in the athletic department.
A call to Sherburne's residence Friday was not returned.
Penn State spokeswoman Lisa Powers confirmed that Sherburne was no longer with the university, but declined to comment on how or why he was let go.
"We do not discuss details surrounding personnel issues," she said.
Contact Susan Snyder at 215-854-4693 or firstname.lastname@example.org, or follow on Twitter @ssnyderinq.