Facebook is concerned after being ordered by Singapore to block access to a news site's page.
The social networking platform said it was "legally compelled" to comply after Singapore said the fringe site States Time Review broke the new "fake news" law and conveyed "falsehoods".
The legistlation - which is known as the Protection from Online Falsehoods and Manipulation bill (POFMA) - was introduced in October last year, with the government insisting it needs strict laws to combat fake news and its potential to incite racial and religious disharmony.
A Facebook spokesman told BBC: "We believe orders like this are disproportionate and contradict the government's claim that POFMA would not be used as a censorship tool.
"We've repeatedly highlighted this law's potential for overreach and we're deeply concerned about the precedent this sets for the stifling of freedom of expression in Singapore."
Authorities calimed the States Time Review (STR) posted in January and "falsely claimed that Singapore had run out of face masks" in relaton to the coronavirus situation.
STR ignored correction directions, as well as a call to post a notice from the Ministry of Communications and Information which would mean anyone visiting the page would be "warned that [it] has a history communicating falsehoods".