CNN  — 

Lab testing for the substance found at the White House on Sunday has come back positive for cocaine, according to a person familiar with the matter.

CNN has reached out to the Secret Service for official confirmation.

The substance was found near the ground floor entrance to the West Wing, the person said. The location is where staff-led tours of the White House pass through on their way into the building.

The substance was found near where guests are asked to leave their cell phones before proceeding into the West Wing.

Those tours typically only occur on weekends.

This is a breaking story and will be updated.