FaceApp, the chart-topping Russian-made which allows users to see how they will look as they age, found itself in the eye of a political storm in the U.S. on Wednesday, with one senator urging an FBI investigation into its “national security and privacy risks”.

In a report by AFP has it that a celebrity favourite, the app deploys artificial intelligence to modify users’ photos, adding wrinkles or subtracting years from their faces.

But, on Wednesday, U.S. Senate Minority Leader Chuck Schumer sounded the alarm over FaceApp’s Russian developer, calling for the FBI and the consumer protection agency FTC to “look into the national security and privacy risks” connected to the application.

“FaceApp’s location in Russia raises questions regarding how and when the company provides access to the data of U.S. citizens to third parties, including potentially foreign governments,” the New York senator said in a letter to the FBI.

“It would be deeply troubling if the sensitive personal information of US citizens was provided to a hostile foreign power actively engaged in cyber hostilities against the United States,” he added.

Currently the most downloaded free app on Google Play with more than 100 million users, FaceApp was launched two years ago and went viral after its latest editing tool, an aging filter, sparked a flood of celebrity selfies.

The developers are based in the Skolkovo high-tech hub near Moscow, often called Russia’s Silicon Valley, and its roots have stirred concern also within the US Democratic Party.

The party’s National Committee has warned campaigners in the primaries ahead of the 2020 presidential election to “delete the app immediately,” the Washington Post said.

The party is particularly sensitive to any possibility of surveillance involving Moscow after some Democratic officials were targeted by Russian hackers during the 2016 presidential election campaign.

Fears of cyber-espionage have flared in recent years, with US authorities worried about foreign governments having access to and potentially misusing personal data belonging to millions of Americans.

In May a Chinese mobile gaming company that bought top gay dating app Grindr said it would sell it by June 2020 following pressure from US authorities.

U.S. officials reportedly feared that people with American security clearances who use Grindr could be blackmailed if China’s government demanded user data from Beijing-based Kunlun Tech.

With millions of users in the US, FaceApp’s Russian backers have not responded to Schumer’s letter.

But its CEO told the Washington Post that Russian authorities did not have any access to any user data.

Yaroslav Goncharov also told the newspaper that most photos are deleted from its servers within 48 hours and said the app did not use the pictures for any other purpose.

FaceApp is no stranger to controversy. Soon after its launch, a ‘hot’ filter that automatically lightened faces sparked accusations of racism.

The same year, FaceApp’s developers were forced to remove a feature that allowed users to change their ethnicity, prompting some to liken the practice to ‘digital blackface’.

But the controversies have done little to dim the app’s allure among selfie-lovers and celebrities including music superstar Drake, rapper Cardi B and NBA champion Steph Curry.