The South Korean data protection authority confirmed to Yonhap News Agency that they found evidence of communication between DeepSeek and ByteDance.
Due to concerns over data privacy, South Korea removed DeepSeek from app stores over the weekend.
DeepSeek made waves in the AI sector back in January, causing a significant drop in global stock markets after claims emerged that its new model was developed at a fraction of the cost compared to US competitors like ChatGPT.
Since then, several countries have raised alarms about the potential mishandling of user data, and in February, a US cybersecurity firm suggested there might be data sharing between DeepSeek and ByteDance.
DeepSeek quickly climbed to the top of app charts in the UK, US, and other nations, although it has since fallen behind ChatGPT in the UK rankings.
In South Korea, the app was downloaded over a million times before it was taken down from Apple and Google’s app stores on Saturday night.
Current users can still access the app through a web browser.
The Personal Information Protection Commission (PIPC) of South Korea informed Yonhap News Agency that while they found a connection between DeepSeek and ByteDance, they have yet to determine what specific data was shared and to what degree.
Critics of the Chinese government have long pointed out that the National Intelligence Law allows the state to access any data from Chinese firms.
However, ByteDance, based in Beijing, has a diverse group of global investors, and some argue that the same law also protects private companies and personal data.
Concerns about user data being sent to China contributed to the US Supreme Court's decision to uphold a ban on TikTok, which is owned by ByteDance.
The US ban is currently on hold until April 5 as President Donald Trump seeks a resolution.
Be careful
Cybersecurity firm Security Scorecard dropped a blog about DeepSeek on February 10, pointing out "multiple direct references to ByteDance-owned" services.
These references indicate a strong connection with ByteDance's analytics and performance monitoring systems, according to their review of DeepSeek's Android app.
Security Scorecard raised alarms about potential privacy issues, noting that DeepSeek "user behavior and device metadata [are] likely sent to ByteDance servers."
They also discovered data "being transmitted to domains associated with Chinese state-owned entities."
On Monday, South Korea's PIPC reported that it "found out traffic generated by third-party data transfers and insufficient transparency in DeepSeek's privacy policy."
They mentioned that DeepSeek was working with the regulator and admitted it had overlooked South Korean privacy laws.
However, the regulator warned users to "be careful and avoid entering personal information into the chatbot."
South Korea has already joined other countries like Australia and Taiwan in banning DeepSeek from government devices.