The Secret Service is ending its investigation into the discovery of cocaine at the White House after failing to identify a suspect, lawmakers briefed on the matter disclosed and the Secret Service confirmed on Thursday.

Emerging from a closed-door briefing in the Capitol sensitive compartmented information facility (SCIF), lawmakers on the House Oversight Committee said the probe will officially end Friday.

“The Secret Service is ending their investigation tomorrow,” Rep. Marjorie Taylor Greene (R-Ga.) told reporters.

“Basically they told us that the investigation will be over tomorrow, they don’t know who it is,” Rep. Tim Burchett (R-Tenn.) said.

Greene said the Secret Service was able to narrow down a list of approximately 500 potential suspects but would not detail who was included because it was classified, only saying that the list included “quite a mix of people.”

The Secret Service briefed the House Oversight and Accountability Committee on the investigation after Chairman James Comer (R-Ky.) sent a letter Friday to Secret Service Director Kimberly Cheatle requesting a “staff-level” briefing on the matter.

The cocaine was found July 2 and days later the Secret Service confirmed that it was in fact the drug. It was found in a lobby area of the West Wing off the West Executive Ave entrance in an area where individuals deposit electronics and personal items prior to entering, the Secret Service told The Hill. Greene said it was left in a cubby in the lobby area.

Rep. Lauren Boebert (R-Colo.) said the Secret Service told lawmakers that .007 grams of cocaine was found. Lawmakers briefed on the matter said the Secret Service does not have a timeline of when the cocaine was left in the White House.

“It could have been that day, it could’ve been a week before, it could’ve been months before,” Rep. Jamie Raskin (Md.), the top Democrat on the panel, told reporters.

The Secret Service confirmed on Thursday that its investigation into how the item entered the White House has concluded due to lack of physical evidence.

The agency said the packaging of the cocaine underwent fingerprint and DNA testing. The Secret Service review “developed an index of several hundred individuals who may have accessed the area where the substance was found” and “developed a pool of known persons for comparison of forensic evidence gleaned from the FBI’s analysis of the substance’s packaging.”

“The substance and packaging underwent further forensic testing. The substance was analyzed for its chemical composition. The packaging was subjected to advanced fingerprint and DNA analysis,” according to the Secret Service, which added that both analyses were conducted by the FBI’s crime laboratory.

The FBI lab results were given to the Secret Service on Wednesday and there were no fingerprints and no sufficient DNA for investigative comparisons so they couldn’t “compare evidence against the known pool of individuals.” There was also no surveillance video footage that could provide a lead.

The Secret Service has been leading the investigation. The White House has stressed that is is taking the investigation seriously but deferred all questions to the Secret Service.

White House principal deputy press secretary Olivia Dalton told The Hill on Thursday that the White House has “been briefed by Secret Service on the outcome of their investigation and are reviewing the information.”

The discovery earlier this month has caused political headaches for President Biden and raised concerns about security at the White House complex. The discovery led to a precautionary closure of the White House complex.

While uncorroborated, conservative media associated the cocaine found to the president’s son Hunter Biden, who has had a history of drug use, despite there being no such links and the fact that neither Hunter nor the president were at the White House on the day of the discovery. The family was at Camp David at the time.

Former President Trump also lashed out at the media for its coverage and questioned: “Does anybody really believe that the COCAINE found in the West Wing of the White House, very close to the Oval Office, is for the use of anyone other than Hunter & Joe Biden.”

Emerging from Thursday’s briefing in the Capitol, Republicans expressed frustration at the Secret Service’s inability to find a suspect in their investigation.

Burchett said he left the briefing early, calling the investigation a “complete failure.”

“This thing is ridiculous… a lot of people are upset about it because they don’t, clearly the Secret Service is failing at their job,” he added.

Greene criticized the Secret Service for not performing drug tests on the 500 potential suspects, and said she asked the agency’s briefers why they would not consider doing so.

“So my question for them were admonishing them along those lines of how can you dare leave that off? It’s a simple drug test. And if there’s a list of 500 people where one of them potentially brought an illegal drug into the White House, that’s a list of 500 people that should go through a simple drug test,” she told reporters.

And Speaker Kevin McCarthy (R-Calif.) argued that the situation amounted to unequal treatment in favor of the Biden administration.

“It seems to me that Biden Inc. strikes again,” McCarthy told reporters. “How can in the White House, 24/7 security, they find cocaine but now they just close the investigation… only with the Bidens in charge there is no equal justice.”

“Anything revolving around Biden Inc. gets treated different than any other American and that’s got to stop,” he later added.

Raskin, however, said he was satisfied with the “thorough investigation.”

Emily Brooks contributed. Updated at 1:45 p.m.