A former US-based executive of ByteDance, the Chinese company that owns TikTok, has sued it for wrongful dismissal, saying he was fired for sounding the alarm over what he called its "culture of lawlessness."
The suit, filed by Yintao Yu in a San Francisco court, comes as political pressure has been growing in the US to ban TikTok. Critics say the popular platform allows Beijing to covertly collect users' data and influence their opinions -- something the company denies.
In his suit, Yu says that he discovered shortly after being hired in 2017 that ByteDance "was stealing" videos published on rival sites like Instagram and Snapchat and presenting them as its own.
Yu, who was ByteDance's US head of engineering, says he notified company leaders about the problem, but the "intellectual property infringement continued unabated."
He was fired in November 2018.
On Friday, Yu submitted an amendment to his original complaint -- which was filed May 1 -- accusing ByteDance of serving "as a useful propaganda tool for the Chinese Communist Party."
He said he had seen ByteDance give prominence to content expressing "hatred for Japan," while playing down posts supporting pro-democracy protesters in Hong Kong.
Yu said that Chinese government officials had a unit in the US office which "maintained supreme access to all the company data, even data stored in the United States."
"My client is the most senior executive at ByteDance to come forward publicly," Yu's lawyer, Charles Jung, told AFP on Saturday.
He added: "My client is concerned about protecting American user data, about the ethical operations of the app and the well-being of ByteDance's employees."
The issue of access to personal data on American users has aroused growing concern among US authorities. In response, the company says it stores that data only on US-based servers.
At a congressional hearing in Washington in late March, TikTok boss Shou Zi Chew again reassured legislators that Beijing had no access to the US data. But several lawmakers expressed disbelief.
The White House recently threatened to ban TikTok in the US unless ByteDance sold it to an American company.
Yu asked the San Francisco court to issue an injunction forcing ByteDance to halt the practices listed in the complaint, and to pay him damages and interest, of which he promised to share a "substantial part" with Asian-American rights groups in the US.
ByteDance and TikTok did not immediately respond on Saturday to an AFP request for comment.