Google turned off its service some time between 5 December 2012 and 8 December 2012
Google has switched off its warning system that notifies its Chinese users that their search results are expected to be censored.
The anti-censorship service, which was launched in May 2012, assisted users in navigating past China's censorship systems.
Authorities had made attempts to block the feature.
The Chinese censorship monitoring body, Greatfire.org, revealed that Google turned off its service some time between 5 December 2012 and 8 December 2012.
Greatfire.org said since Google moved its search engine to Hong Kong in 2010, the "Great Firewall" censored YouTube, GooglePlus and thousands of keywords on Google search.
Google had no control over its services being blocked.
"This latest move was fully controlled by Google and can as such only be described as self-censorship," Greatfire.org said.
While the government made attempts to block the alert function, Google had tried to change the URL of the file as some its users were being completely blocked from Google search.