Washington, Jul 14 (IANS): The US Secret Service has ended its investigation of cocaine discovered at the White House earlier this month.

A zip-close bag which had some white powdery substance was discovered by Secret Service officers on July 2 in a common storage area on the ground floor of the West Wing, which houses the Oval Office and offices of some of the President's top aides and support staff.

The discovery had led to a brief shutdown of the White House.

Tests on the material determined it was cocaine, and further analysis was carried out on the composition of the substance, the BBC reported.

In a statement on Thursday, the Secret Service said that it had attempted to determine a suspect through fingerprints, DNA traces and video evidence, but had not been able to do so.

On Wednesday, the Secret Service received the forensic evidence back from the FBI. This showed it did not have enough DNA evidence for comparison, and had not developed "latent fingerprints".

"Therefore, the Secret Service is not able to compare evidence against the known pool of individuals," the BBC quoted the statement as saying.

It added that the surveillance footage had also not been of use, and it would mean trying to single out someone from "hundreds of individuals" who passed through the area -- without having any physical evidence to do so.

The Secret Service added that it "takes its mission to protect US leaders, facilities, and events seriously" and it is "constantly adapting to meet the needs of the current and future security environment".

President Joe Biden and his family were at Camp David in Maryland at the time of the incident.