Socio-commentary website Breakfast Network has shut down after it decided not to register with the Media Development Authority.
Netizens can no longer log onto the site or access articles that have been posted since the portal went online eight months back.
The MDA said in a statement on Tuesday that the website, founded by former Straits Times associate editor Bertha Henson, will have to cease its online service as it "will not be complying with the registration notification".
An MDA spokesman said the authority had asked the site owners of Breakfast Network on Nov 26 to register under the Broadcasting (Class Licence) Notification.
The Dec 10 registration deadline was extended by a week, at the request of site owners, said the MDA statement.
By registering with the MDA, Breakfast Network had to undertake not to receive foreign funding. The move was also meant to guard the site from foreign influence or funding, thus "ensuring that Singapore politics remain a matter for Singaporeans alone", the spokesman added.
"The registration of Breakfast Network upholds the firmly-established principle that foreign entities may not engage in Singapore politics or be allowed to control or worse, manipulate our local media platforms, which are prime vehicles for political influence."
Ms Henson had announced that she would be suspending website's operations in a final post on the site on Monday night. She said the group needed to "regroup, rethink and restrategise".