Under Protection from Online Falsehoods and Manipulation Act (Pofma), the States Times Review was required to carry a correction notice on its Facebook post stating that its article contains falsehoods.
The States Times Review post contained accusations about the arrest of an alleged whistleblower and election-rigging.
Facebook issues first-ever "fake news" correction to user post under pressure from Singapore govt For the first time, Facebook has given into pressure from Singapore to add a correction notice on a post which officials have deemed "fake news", shared on the platform by a blogger.
Singapore authorities had previously ordered STR editor Alex Tan to correct the post but the Australian citizen said he would "not comply with any order from a foreign government".
Reuters reports Facebook saying in an emailed statement, "As required by Singapore law, Facebook applied a label to these posts, which were determined by the Singapore government to contain false information".
However, Mr Tan refused the correction, writing on his blog that "The site is based in Australia and it obeys only Australian jurisdiction". "As it is early days of the law coming into effect, we hope the Singapore Government's assurances that it will not impact free expression will lead to a measured and transparent approach to implementation", it said.
The notice, now placed at the bottom of Tan's post, is designed only to be visible to Facebook users in Singapore. Facebook couldn't instantly explain why the notice was unavailable to some users.
Facebook often block content that the government was accused of violating local laws, with almost 18,000 cases globally in the year to June, according to the company "transparency report".
This is the second time last week that the country's law against online falsehoods had been invoked, with the first issued last Monday, November 25, which had to do with a Facebook post from Brad Bowyer. The law also bans the use of fake accounts or bots to spread fake news, with penalties of up to S$1m (£563,000, $733,700) and a jail term of up to 10 years.
The Asia Internet Coalition, an association of internet and technology in the region, called the law "the most far-reaching legislation of its kind to date", while rights groups say it could undermine the freedom of the Internet, not only in Singapore, but elsewhere in Southeast Asia.