Los Angeles, California (CNN) -- A threatening letter with white powder inside caused a scare at the "Dancing With The Stars" production office, authorities said.
Security and city authorities were immediately notified after the letter arrived Friday evening, ABC spokeswoman Amy Astley said in a statement.
Investigators later advised ABC that the substance inside was talcum powder, Astley said.
"Measures were taken to secure the area and ensure the safety of personnel," she said.
A field screening by FBI and Los Angeles Police did not detect hazardous substances at the show's CBS Studios site, FBI spokeswoman Laura Eimiller said in a statement.
The letter will be tested further at a regional laboratory as authorities' investigation continues, Eimiller said.
CNN's Brittany Kaplan contributed to this report.