The House Oversight Committee has begun an investigation into the discovery of a tiny bag of cocaine on the lower level of the West Wing, not far from the Situation Room. This is just one of the many ongoing investigations that the panel has launched in recent months, including into the president’s family. 

In a letter sent Friday to the director of the Secret Service, Kimberly Cheatle, the Oversight Committee chairman, Congressman James Comer, asked for a staff-level briefing from the agency about the security breach that led to the drugs being smuggled into what is arguably the nation’s most secure building.

“In order to assist the Committee with its investigation, please provide a staff level briefing on this matter by July 14,” Mr. Comer wrote to Ms. Cheatle. 

In a press release, the chairman’s office said the discovery of cocaine in the West Wing “requires” that the committee “assess White House security practices and determine whose failures led to an evacuation of the building.”

“The presence of illegal drugs in the White House is unacceptable and a shameful moment in the White House’s history,” Mr. Comer said in a statement. “Congress funds White House security procedures, and the Secret Service has a responsibility to maintain effective safety protocols. This incident and the eventual evacuation of staff now clearly raises concerns about the level of security maintained at the White House.”

A White House official confirmed to NBC News that the Secret Service would test the bag of cocaine for “DNA, fingerprints and a full chemical analysis,” as well as reviewing security tapes. 

When the illicit substance was discovered and the White House was evacuated on Sunday, President Biden and his family, including Hunter Biden, who is a recovering cocaine addict, were at Camp David. 

Republicans have been raising alarms about the security of the White House since the discovery of cocaine was first reported. On Wednesday, Senator Cotton sent his own set of queries to Ms. Cheatle in order to gain more information about her department’s security protocols and how it plans to prevent such breaches. 

The White House press secretary, Karine Jean-Pierre, and the deputy press secretary, Andrew Bates, have consistently referred questions about the incident to the Secret Service, which is expected to conclude its investigation in the coming days. 

Yet when asked about the investigation at a press briefing on Friday, Ms. Jean-Pierre admonished a reporter for even raising the issue. “Can you say once and for all whether the cocaine belonged to the Biden family?” a reporter asked the press secretary, which elicited laughs in the room. 

Ms. Jean-Pierre then sternly said that members of the press were not acting appropriately in asking such questions. “There has been some irresponsible reporting about the family, so I’ve got to call that out here,” she said. “I’ve been very clear … the Biden family was not here. They were at Camp David.”

“To ask that question is incredibly irresponsible,” Ms. Jean-Pierre said to the reporter. 

The national security advisor, Jake Sullivan, who attended the briefing to discuss Mr. Biden’s upcoming trip to Europe, said White House staff would be punished if it turns out they were involved with the substance. 

“If it involves someone from the White House, the appropriate consequences will ensue,” he said.