Google has reported that all of its services are being blocked in mainland China.
The company said on its Transparency Report site that all of its services were being blocked within the country, citing a report from Bloomberg.
GreatFire.org, a site which monitors China's web filtering technology, often dubbed the Great Firewall, noted that the move could have a major impact in China, where Google services are believed to have hundreds of millions of users.
"Facebook, Twitter and YouTube were all blocked before they attracted more than a small number of users in China," the site said.
"We've argued before that the authorities didn't dare to fully block GMail since it has too many users already. Fully blocking Google goes much further."
The Chinese government has a history of placing partial or total blocks on search or social networking platforms which are run outside of the country and don't allow for its censorship and filtering policies to be enforced.
Google has found itself at odds with authorities in China a number of times over the years. The company has long opposed the nation's extensive use of web filtering and censorship technologies.
In 2010, Google was among the dozens of firms targeted in Operation Aurora, an attack which was alleged to have been conducted by state-sponsored groups within China.