The popularity of the short-form video app TikTok has exploded recently.

But, now its owner is reportedly the subject of a U.S. national security investigation.

Chinese firm ByteDance bought the app ‘Musical.ly’ in 2017, eventually turning it into the teenage sensation known as TikTok.

TikTok takes you into a world of cute dogs and random acts of kindness

According to reports, the U.S. Treasury’s Committee on Foreign Investment is now investigating it as a potential national security risk, citing allegations of censorship on politically sensitive content and raising questions over how it stores personal data.

Republican Senator Marco Rubio recently tweeted out his concerns about TikTok, claiming the company must “turn over data” to the Chinese government if asked.

The top Democrat in the Senate, Chuck Schumer also wrote this letter to the Pentagon, urging the Secretary of the Army to “assess the potential national security risks posed by China-owned technology companies before choosing to utilize certain platforms.”

In a statement last month, TikTok said: “Our data centers are located entirely outside of China, and none of our data is subject to Chinese law. We have never been asked by the Chinese government to remove any content and we would not do so if asked.”

The Reuters news agency also reports the committee is in talks with TikTok about how to maintain its assets in the U.S.

Whatever happens with the investigation, there’s no guarantee TikTok will keep growing.

Another video-sharing platform, ‘Vine’, was shut down by its owner Twitter after its popularity plunged and it dropped out of Apple’s top 100 free apps.