A collection of pictures censored on Chinese Twitter-like service Sina Weibo has been revealed.

Analysis from US investigative journalism group ProPublica logged 100 users on the service, discovering a total of 527 images removed by censors.

The sample data – which was collected over two weeks – contained dissidents, a yawning politician, and archive shots from the Korean War.

Sina Weibo has some 500 million users in China, but is closely monitored.

ProPublica selected a group of users that had previously had material removed from the site, with a focus on journalists, lawyers and other figures with significant numbers of followers.

Sina Weibo has some 500 million users in China, but is closely monitored

The site – with help from the University of Hong Kong – wrote some software that would store posts from the users, and then check on an hourly basis to see if the posts had been removed.

What they found was a wide ranging selection of images deemed not suitable for dissemination on the site.

The collection included images of Bo Xilai, the former high-ranking Chinese politician, who was jailed in October for bribery, embezzlement and abuse of power.

One deleted post had called for the trial to be broadcast live, while another showed Bo Xilai with former US national security adviser Henry Kissinger.

Pictures of other public figures, such as human rights advocate Xu Zhiyong and activist singer Wu Hongfei, were also removed.

A large number of the censored posts monitored were of long passages of text, ProPublica reported.

A service called Long Weibo – comparable to TwitLonger – allows for posts that go beyond the service’s 140-character limit by creating an image showing Chinese characters.

The popularity of Long Weibo has created a censorship headache for authorities as it means banned words are not automatically flagged.