A congressional oversight committee has launched an inquiry into possible meth production at a government lab in Maryland and is seeking building-access records to track the movements of a former employee, congressional staffers said Wednesday.

The employee, who served as a police lieutenant at the sprawling campus of the National Institute of Standards and Technology, resigned July 19, the day after he was injured during an explosion inside a NIST building. The incident happened about 7 p.m. on a Saturday while he was on duty. Officials said that chemicals found at the scene were consistent with the manufacture of methamphetamine, or meth, a highly addictive street drug.

The officer, who had recently served a brief term as acting police chief of NIST’s Gaithersburg campus, has not been charged. The FBI is leading a criminal investigation.

Separately, the U.S. Congressional Committee on Science, Space and Technology received a briefing Wednesday about the incident from NIST Director Willie E. May. He indicated that whatever happened hadn’t been going on long, said Zachary Kurz, a spokesman for the committee. May declined to say whether NIST had determined whether the former lieutenant was making meth, saying that matter is under investigation by law enforcement agencies outside of NIST, according to Kurz.

In a statement Wednesday, the committee chairman, Rep. Lamar Smith (R-Tex.), said he was troubled by what he knew so far — particularly that the subject of the investigation served as a high-ranking NIST police officer.

“Even Hollywood couldn’t have imagined this plot twist,” Smith said. “As the science committee expands its investigation, it is becoming clear we must better monitor those with access to our nation’s high-tech research facilities.”

NIST, a branch of the Commerce Department, usually makes news for its high-level research. Among their other pursuits, scientists there have earned several Nobel Prizes for their study of atomic physics.

According to a committee aide, two members of NIST’s police force were on duty the night of July 18 when an explosion erupted inside a room in Building 236, which is reserved for special projects and sits on the southern edge of the 578-acre campus. The room was not being used for active NIST research, a spokeswoman for the institute said, and was designed as a place to conduct “combustion research.” The explosion didn’t damage the structure, she said. The windows, which were designed not to shatter, were blown out whole and fell to the ground.

The explosion set off a heat alarm. NIST firefighters and at least one other NIST police officer responded. They found the lieutenant, who initially said he was trying to fill a butane lighter, according to the committee aide and a law enforcement official with knowledge of the case.

The lieutenant, who had worked for NIST for about 13 years, was treated and released from a local trauma center.

Smith, the committee chairman, wants to get data on the former lieutenant’s movements at NIST, perhaps via electronic lock records, so that his committee’s staff can determine how much time the officer had spent in Building 236 in recent months. Smith also wants to know what kind of background checks NIST conducts before hiring police officers.