A video going viral on social media shows Malia Obama, US President's elder daughter, smoking something that looks like a cigarette.
The video has sparked off speculations over whether she was smoking marijuana.
18-year-old Malia was at the Lollapalooza music festival in Chicago, Illinois last month where she was captured on video while smoking.
In the nine-second video, published by Radar Online, a young woman in the foreground is seen dancing and sticking her tongue out while Malia Obama is seen in the background.
The website claims an eyewitness had smelled cannabis in the air.
Cannabis is decriminalised in the state of Illinois and people are allowed to possess up to 10 grams of the drug.
Malia Obama is currently on a gap year before going to Harvard in the autumn of 2017.
Malia’s younger sister Sasha Obama, 15, has undertaken a summer job in a fish restaurant in Martha's Vineyard of Massachusetts.