White powder that sparked a brief evacuation of the White House was cocaine, sources said.

Officials found the powder – in a small plastic envelope – in the heavily trafficked West Wing lobby on Sunday.

They immediately suspected illegal drugs but ran tests to make sure the powder was not something more dangerous.

Investigators have yet to find the person who took the cocaine into the White House, said sources, who are three people unauthorised to talk publicly about the inquiry.

US President Joe Biden was at Camp David with relatives for the Independence Day holiday weekend when the powder was discovered and the complex was briefly evacuated as a precaution.

It is routine for emergency teams to quickly test a suspicious substance on the scene to determine whether it is hazardous and follow up with a more sensitive lab tests later.

The US Secret Service, which is responsible for securing the White House, was taking the lead on the investigation, consulting visitor logs and security footage.

The lobby is where many official visitors and workers enter.

It is also open to staff-led tours of the West Wing, which are scheduled for nonworking hours on the weekends and evenings.

The Secret Service said in a statement on Tuesday that the White House was closed as a precaution as emergency crews investigated, and that the District of Columbia Fire Department was called in to evaluate and determine that the substance was not hazardous.

“The item was sent for further evaluation and an investigation into the cause and manner of how it entered the White House is pending,” the Secret Service said.