Topics often suppressed by the Chinese government within its borders, including Tibet, Hong Kong protests and the Uyghur population, appear to be unusually underrepresented on TikTok compared with Instagram, according to a report published Thursday by online researchers.
The findings could add to a wave of concern that Beijing may be influencing content on the popular video platform. TikTok is owned by ByteDance, a Chinese company.
The report, from the Network Contagion Research Institute at Rutgers University, analyzed the volume of posts with certain hashtags on TikTok and Instagram, which has hundreds of millions more users.
For popular pop culture and politics terms like #TaylorSwift and #Trump, the researchers found roughly two Instagram posts for every one on TikTok, the report said. But that ratio jumped to more than 8-to-1 for #Uyghur or #Uighur, 30-to-1 for #Tibet, 57-to-1 for #TiananmenSquare, and 174-to-1 for #HongKongProtest.
“We assess a strong possibility that content on TikTok is either amplified or suppressed based on its alignment with the interests of the Chinese government,” the report said. Joel Finkelstein, a founder of the Network Contagion Research Institute, said, “It’s not believable that this could happen organically.”
TikTok, which has said repeatedly that the Chinese government has no influence over the app, pushed back on the research.
“The report uses a flawed methodology to reach a predetermined, false conclusion,” said Alex Haurek, a spokesman for the company. Mr. Haurek said that hashtags were created by users, not by TikTok, and that “anyone familiar with how the platform works can see for themselves the content they refer to is widely available and claims of suppression are baseless.”
The company added that one-third of videos viewed on TikTok do not have any hashtags and that Instagram had been around longer.
The Israel-Hamas war has reignited concerns about how social media platforms moderate content, and TikTok has been especially scrutinized. TikTok has been accused of pushing pro-Palestinian, anti-Israel content to young Americans, which the company has called unfair and inaccurate. But the allegations have fueled new questions from lawmakers and researchers on how Beijing might influence content on TikTok, especially as the app grows as a news source for Americans under 30.
Several Republican lawmakers have renewed calls to regulate or ban TikTok. A bipartisan committee of House representatives requested a classified briefing from the F.B.I. by the end of this week that would detail its efforts involving ByteDance, TikTok and potential surveillance. A spokesman for the group did not respond to a request for comment on whether the briefing had occurred.
Representative Josh Gottheimer, Democrat of New Jersey, said the report showed that TikTok was “a tool to brazenly spread disinformation and suppress content that undermines the Chinese government.”
Mr. Finkelstein said that his group pursued its study after TikTok, in response to criticism about content related to the Israel-Hamas war, said hashtags like #FreePalestine were also more prevalent than #StandWithIsrael on Instagram and Facebook. He added that the report employed methodology similar to TikTok’s.
Mr. Haurek of TikTok disputed that assertion. “Suggesting that this report employed TikTok’s methodology is false, and we have repeatedly made clear that comparing hashtags is an inaccurate reflection of on-platform activity,” he said.
Joshua Tucker, a co-director of the Center for Social Media and Politics at New York University, warned against drawing too firm of a conclusion from the institute’s report. He said that people could post about different topics depending on what platform they were on or leave tags off certain photos and videos, for example.
Academic and civil society researchers have been urging TikTok to give them access to data to study the spread of information on the app. Mr. Tucker said the N.C.R.I. report was a reminder of the need for that access.