The Food and Drug Administration seized "thousands of pages of documents" in a surprise inspection of e-cigarette maker Juul's San Francisco headquarters last week, the agency said Tuesday.
The FDA is looking into the company's marketing practices as Commissioner Scott Gottlieb calls teen use of nicotine vaping devices an "epidemic."
It builds on the agency's request in April for company materials related to how Juul products appeal to kids. The most recent inspection, conducted Friday, "sought further documentation related to Juul's sales and marketing practices, among other things," FDA said in a statement.
Juul did not immediately have comment.
U.S. & World
Stories that affect your life across the U.S. and around the world.
The inspection comes weeks after the FDA announced a crackdown that requires e-cig manufacturers, including Juul, to submit plans to address youth use of their products within 60 days. The agency also threatened to ban some flavored nicotine liquids, which critics say attract kids to e-cigarettes.
Juul has been at the center of the FDA's attention this year as e-cigarette use soars among teens.
Over the past year, the number of high school students who have used e-cigarettes in the past 30 days has skyrocketed by about 75 percent, preliminary data from the Centers for Disease Control and Prevention's annual National Youth Tobacco Survey show, according to people familiar with the data. They asked not to be identified because the report isn't yet public.
This story first appeared on CNBC.com. More from CNBC: