Popular Chinese apps TikTok and WeChat have been accused of increasingly censoring content globally, taking practices honed for years behind the Great Firewall to an international audience.
A new report by the Australian Strategic Policy Institute (ASPI) claims viral video app TikTok hides search results for a series of searches in eight languages.
Searches for terms including "GayArab," as well as "Putin is a thief" in Russian and "Why do we need a king" in Thai do not return results, the study found.
ASPI researchers found that searches for these topics weren't only censored in individual countries, but search results for these terms were hidden around the world.
"Implementing specific countries' rules across the platform means that Arabic-speaking people around the world, even those who live in countries where homosexuality is legal, are prevented from accessing content related to these hashtags on TikTok," the researchers wrote in the report.
It was reported this year that internal TikTok moderation guidelines had instructed employees to remove videos about politicians such as Vladimir Putin, Donald Trump and Kim Jong Un.
In May, TikTok said a "technical glitch" had caused videos tagged with the phrases "BlackLivesMatter" and "GeorgeFloyd" not to show up in search results in the app.
TikTok faces mounting political scrutiny in the US over national security concerns which may lead to the sale of its US operations.
A joint bid between Microsoft and supermarket chain Walmart has emerged as a leading potential buyer, but new Chinese export restrictions that block the sale of TikTok's video recommendation system have delayed negotiations.
Tiananmen Square images 'hidden'
ASPI also claimed in its report, which was funded by the US State Department, that users of the Chinese messaging app WeChat around the world also face censorship when the app hides content relating to Chinese politics.
Images related to the Tiananmen Square protests were hidden from other WeChat users, ASPI found, and some people's accounts were suspended for sharing the images.
Some diplomatic posts published by the UK, US and Indian governments were also censored, the report claimed.
It found that some web links published on WeChat by the governments were disabled so users could not follow them to find out more information.
TikTok blames 'bug' and local laws
A TikTok spokesman told ASPI: "As part of our localised approach to moderation, some terms that the ASPI provided were partially restricted due to relevant local laws."
"Other terms were restricted because they were primarily used when looking for pornographic content, while the Thai phrases the ASPI supplied are either readily found when searched or do not appear to be hashtags that any TikTok users have added to their posts."
The company also told ASPI that a bug had caused some compound Arabic phrases not to show any results because part of the search terms could have shown pornographic videos.
A WeChat spokesman did not respond to a request for comment.
-Telegraph Group Ltd