BOSTON (AP) — A Northeastern University employee who said he was injured when a package he was opening on the Boston campus exploded last month was charged Tuesday with fabricating the incident.

Jason Duhaime, who is the new technology manager and director of the university's Immersive Media Lab, was charged with “conveying false and misleading information related to an explosive device” and then lying to federal investigators, according to court documents.

Duhaime told investigators that the hard plastic case exploded when he opened it on Sept. 13, causing “sharp” objects to fly from the case and injure his arms, but his arms only had superficial marks and there was no damage to his shirt, investigators said.

According to the FBI affidavit, “The inside and outside of the case did not bear any marks, dents, cracks, holes, or other signs that it had been exposed to a forceful or explosive discharge of any type or magnitude.”

The case also contained a rambling note that railed against virtual reality, referenced Facebook founder Mark Zuckerberg, and threatened to “destroy” the lab.

But the affidavit said the typed letter was “pristine” and “bore no tears, holes, burn marks, or any other indication that it had been near any sort of forceful or explosive discharge.”

Investigators also discovered a word-for-word, electronic copy of the letter stored in a backup folder on a university computer in Duhaime's office.

The affidavit did not suggest a motive and it was not clear when Duhaime, who lives in Texas, would make his first court appearance.

An attorney for Duhaime did not immediately respond to a telephone message and an email seeking comment. Duhaime has previously denied staging the incident, saying in an interview with The Boston Globe that it was “very traumatic.”

“I did not stage this … No way, shape or form ... they need to catch the guy that did this,” he told the newspaper.

The reported explosion led to swarms of police including two bomb squads descending on the school, forced the evacuation of several campus buildings, and put the campus on edge even after reassurances from the school that it was safe.

It marked one of the first big scares in Boston since 2013, when two bombs planted near the finish line of the Boston Marathon killed three spectators and wounded more than 260 others.