Zaira Wasim, who starred in the hit Bollywood film Dangal, is accusing a man on her Delhi-Mumbai flight of touching her inappropriately with his foot.
The 17-year-old Indian actress tried to document the alleged incident on Instagram on Sunday and her posts were then shared by fans. According to Indian news reports, a man has been arrested.
She also streamed an emotional message online to her more than 400,000 followers after arriving at her destination. Even though Instagram stories automatically disappear after 24 hours, the video was re-posted by others.
"No one will help us if we don't decide to help ourselves," Wasim said between tears. "And this is the worst thing."
The BBC captured a screengrab of one of Wasim's posts before it was gone, in which she wrote: "He kept nudging my shoulder and continued to move his foot up and down my back and neck."
The airline, Vistara, said in a series of statements on Twitter that officials are investigating what happened and "stand firm against any kind of harassment."
"Necessary details" have also been passed on to police, the statement said.
Official Statement: Update #3 pic.twitter.com/wd1RbK4uk6— @airvistara
In another statement, the company said the "crew only became aware of something amiss during final descent when they were seated for landing."
The 2016 smash hit Dangal, in which Wasim made her acting debut, is the highest-grossing Indian film ever. She won multiple awards and is a budding role model for young girls in India.
Wasim's public message comes in the wake of #metoo, a worldwide movement to share common experiences of sexual harassment, assault and misconduct.