According to a relative, three Beijing-based internet activists have disappeared and are believed to have been arrested by the police for archiving censored coronavirus messages online.
China has been criticized for dealing with the outbreak, including punishing whistleblowers who attempted to warn of the new virus.
Chen Mei, Cai Wei, and his girlfriend Tang, who contributed to the crowd sourcing project on the GitHub software development platform, disappeared on April 19, according to Chen's brother Chen Kun.
The volunteer project, Terminus2049, preserved articles that have been blocked by China's aggressive online censorship or removed from mainland news agencies and social media.
Two of the volunteers, Cai and Tang, were accused of "addressing disputes and provoking anger." They are currently "monitored in residential areas" at a specific location. According to a statement by the Chaoyang District Police in Beijing, who received their families and saw them from AFP.
Chen Kun said he is still waiting for the official confirmation from the Chaoyang police that his younger brother, 26, has been arrested.
"I understand that Cai and Tang disappeared around the same time as Chen Mei," Chen told AFP.
"Given that both Chen and Cai have contributed to the Terminus2049 project, we suspect that their disappearance is related to the project and relevant."
The online project included many sensitive corona virus stories released in the past few months, such as personal stories from Wuhan citizens and a notorious interview with Wuhan Central Hospital doctor, Ai Fen, one of the earliest virus whistleblowers.
The article, published by People magazine in March, has been widely distributed by Chinese Internet users in a variety of languages and formats, including Morse code, to avoid censorship after it was abruptly removed from the Internet.
While China is trying to control the domestic narrative about the chaotic first months of the outbreak, similar crowd sourcing initiatives have developed on GitHub, which are being used by more and more tech-savvy Chinese as the final frontier against the increasingly severe internet censorship.
Microsoft's US-based website remains accessible in China, although the Terminus2049 page is blocked.
The news of the disappearance of the Terminus2049 trio caused a stir in Chinese activist circles online.
"What disputes did they choose and what problems did they provoke? Show me legal evidence," said Tsinghua University professor of sociology, Guo Yuhua, on Twitter on Sunday, referring to Cai and Tang's charges.