US investigative journalism group ProPublica monitored 100 Sina Weibo user accounts to see which images were censored on China's version of Twitter.
The organization collaborated with outside researchers to collect posts and reposts made by the accounts starting on July 3, 2013, creating a database of nearly 80,000 posts.
Its analysis showed that of the posts it monitored, 527 contained images that were censored by Sina Weibo between July 24 and Aug. 4.
The sample data collected by ProPublica contained a wide variety of images deemed not suitable for the site, including pictures of jailed politician Bo Xilai, who was convicted of bribery, embezzlement and abuse of power. One of the photos showed Bo with former US national security adviser Henry Kissinger and another post called for Bo's trial to be broadcast live.
More from GlobalPost: Study reveals Chinese censorship of Weibo
Pictures of people like human rights advocate Xu Zhiyong, as well as activist and singer Wu Hongfei, were also removed from the Twitter-like site.
ProPublica noted that many of the censored posts it monitored were of long passages of text.
While a large amount of posts censored included images of Chinese dissidents, the most common type of deleted post was of political speeches portraying the government or Communist Party in a negative light, and any text with anti-government ideas.
Posts on Sina Weibo can exceed the 140-character limit when a service called Long Weibo is used, which creates an image showing Chinese characters. Long Weibo's popularity has made censorship more difficult for authorities as words banned from the site are not automatically flagged.