LONDON – TikTok is facing a fresh European Union privacy investigation into user data sent to China, regulators said Thursday.

The Data Protection Commission opened the inquiry as a follow up to a previous investigation that ended earlier this year with a 530 million euro ($620 million) fine after it found the video sharing app put users at risk of spying by allowing remote access their data from China.

The Irish national watchdog serves as TikTok’s lead data privacy regulator in the 27-nation EU because the company’s European headquarters is based in Dublin.

During an earlier investigation, TikTok initially told the regulator it didn’t store European user data in China, and that data was only accessed remotely by staff in China. However, it later backtracked and said that some data had in fact been stored on Chinese servers. The watchdog responded at the time by saying it would consider further regulatory action.

“As a result of that consideration, the DPC has now decided to open this new inquiry into TikTok,” the watchdog said.

“The purpose of the inquiry is to determine whether TikTok has complied with its relevant obligations under the GDPR in the context of the transfers now at issue, including the lawfulness of the transfers,” the regulator said, referring to the European Union’s strict privacy rules, known as the General Data Protection Regulation.

TikTok did not respond immediately to a request for comment.

TikTok, which is owned by China’s ByteDance, has been under scrutiny in Europe over how it handles personal user information amid concerns from Western officials that it poses a security risk.

Under GDPR, European user data can only be transferred outside of the bloc if there are safeguards in place to ensure the same level of protection. Only 15 countries or territories are deemed to have the same data privacy standard as the EU, but China is not one of them.