A white substance that sparked an emergency evacuation at the White House has tested positive for cocaine.

During a routine inspection of the secure building, the US Secret Service found the substance in a work area.

Sources from the fire and law enforcement departments first reported the preliminary positive test in the Washington Post.

When the substance was discovered, Joe Biden and his family were away at Camp David.

According to the BBC, Secret Service officers discovered white powder “inside a work area” of the West Wing around 20:45 local time on Sunday.

Guglielmi said he quickly called the fire department, who found the substance to be “non-hazardous”.

According to him, the item has been sent for more testing and an investigation is ongoing, including how the substance entered the White House.

The BBC’s US partner, CBS News, reported a senior law enforcement source as saying the substance was found in a storage facility in a cupboard routinely used by White House staff and guests to store mobile phones.

CBS reported that two law enforcement officials and a recording of a radio dispatch from Sunday confirmed the substance tested positive for cocaine soon after it was found.

Cocaine is a Schedule II drug under the Controlled Substances Act, meaning it has a high potential for abuse, according to the US Drug Enforcement Administration.

The West Wing is a large, multi-level part of the White House that contains the offices of the president of the United States, including the Oval Office and the Situation Room.