US Senate leader Chuck Schumer has called for an FBI investigation into FaceApp, an application that changes users' pictures to make them younger or older, the BBC reported.
In a letter posted on Twitter, Schumer said he was worried that the personal data of the Americans could become "a hostile foreign power."
FaceApp denied the accusations.
Wireless Lab, a St. Petersburg company holding the application, said it did not store the photos and did not collect the data, but only uploaded certain photos selected by the users to edit them.
"Although most of the team is located in Russia, user data is not transferred to Russia," says a company release sent to TechCrunch.
Schumer however demanded that the FBI and the Federal Trade Commission investigate FaceApp.
"I have serious concerns about both the protection of data that is collected and the fact that users are unaware who has access to their data," the letter said.
Schumer's appeal comes after the National Democratic Committee had asked candidates in the 2020 elections not to use the application.
The application has around 80 million users globally.