The Singapore-based website Truth Warriors falsely claims that coronavirus vaccines are not safe or effective – and now it will have to carry a correction on the top of each page alerting readers to the falsehoods it propagates.

Under Singapore’s “fake news” law – formerly called the Protection from Online Falsehoods and Manipulation Act – the website must carry a notice to readers that it contains “false statement of fact,” the Health Ministry said Sunday. A criminal investigation is also underway.

Singapore has one of the world’s farthest-reaching anti-misinformation laws enacted in recent years. Rights groups, however, have warned that the law’s broad scope could be used to hinder free speech and target government critics.

That’s a particular concern in a place such as Singapore, which severely restricts political speech. Other countries have modeled similar legislation after Singapore’s.

The Singapore law “is especially appealing to other authoritarian governments that are looking for less-draconian ways to control the narratives, stifle dissenting voices and legitimize their actions,” Masato Kajimoto, an assistant professor at the University of Hong Kong’s journalism school who researches misinformation in Asia, previously told The Washington Post.

At the same time, governments have struggled to combat the proliferation of false and misleading information about the coronavirus and vaccines against it. People in many communities are also hesitant to get the shots because of long-standing distrust of their governments, health systems and Western pharmaceutical companies.

The “Truth Warriors” website “mislead people into thinking that COVID-19 vaccines are not effective in reducing transmission rates” contrary to “the weight of international evidence” showing that the shots safely reduce the risk of infection and serious illness, Singapore’s health ministry said in a statement.

The website also promoted false information about ivermectin, an antiparasitic drug promoted by vaccine skeptics as an alternative to vaccines without any scientific evidence that it cuts covid-19 transmission.

“Ivermectin is a prescription-only medicine registered in Singapore specifically for the treatment of parasitic worm infections,” the ministry of health said in a statement. “Anyone convicted of the illegal sale of these medicines faces a penalty fine of up to $50,000 and/or imprisonment for a period of up to two years under the Health Products Act.”

While vaccine misinformation and disinformation often take on localized contexts, anti-vaccine movements have effectively used social media to magnify their messaging across borders and communities.

Inconsistent public health messaging around issues such as the vaccine’s safety for pregnant people – they are safe and recommended – and effectiveness against infection – never a foolproof guarantee – also created openings for anti-vaccine movements to exploit. Though pharmaceutical companies did accelerate the final leg of researching and developing the shots, for example, the technologies behind the coronavirus vaccines had been in the works for years.

“These materials are from unverified and dubious sources, and individuals who heed the advice of Truth Warriors can endanger themselves and the people around them,” Singapore’s health ministry said.

Around 84 percent of Singapore’s population is fully vaccinated, according the country’s Straits Times newspaper. It has begun administering booster shots to those eligible.

Singapore is mainly offering vaccines produced by Pfizer-BioNTech and Moderna, which use mRNA technologies and studies have shown are most effective in cutting coronavirus transmission and COVID-19 hospitalizations. The Chinese-made Sinovac vaccine is also available, but Singapore will require an additional third dose for a person to be considered fully vaccinated because of its comparatively lesser effectiveness.