WASHINGTON (NewsNation) — The mystery of who brought cocaine into the White House remains unsolved, as there are no leads on who brought the drugs into the building.

No fingerprints or DNA turned up on the baggie of cocaine found in a lobby at the White House last week despite a sophisticated FBI crime lab analysis, and surveillance footage of the area didn’t identify a suspect, according to a summary of the Secret Service investigation. 

U.S. Secret Service agents found the white powder during a routine White House sweep on July 2, in a heavily trafficked West Wing lobby where staff go in and out and tour groups gather to drop their phones and other belongings.

“Without physical evidence, the investigation will not be able to single out a person of interest from the hundreds of individuals who passed through the vestibule where the cocaine was discovered,” Secret Service officials said in the summary.

The presence of cocaine at the White House prompted a flurry of criticism and questions from Republicans, who requested a briefing Thursday on the probe. White House press secretary Karine Jean-Pierre said President Joe Biden believed it was “incredibly important” for the Secret Service to get to the bottom of how the drugs ended up in the White House.

“I don’t know if it’s a diversion or not, because it’s a pretty good diversion. A lot of people are upset about it because they don’t clear the Secret Service,” Rep. Tim Burchett (R-TN) said outside the Secret Service briefing Thursday.

The Secret Service is responsible for securing the White House and is leading the investigation. The bag was sent for a secondary, more sensitive lab analysis. Homeland Security’s National Biodefense Analysis and Countermeasures Center analyzed the item for any biothreats. Tests conducted at the facility came back negative and gave formal confirmation that the substance was not a biological threat.

The lobby is also open to staff-led tours of the West Wing, which are scheduled for nonworking hours on the weekends and evenings. Those tours are invitation-only and led by White House staff for friends, family and other guests. Most staffers who work in the complex can request an evening or weekend tour slot, but there is often a long wait list. There were tours on the day, a Sunday, the drugs were found, as well as on the two preceding days.

The cocaine and packaging underwent further forensics testing, including advanced fingerprint and DNA work at the FBI’s crime laboratory, according to the summary. The FBI also did chemical testing.

The Associated Press contributed to this report.