The grip on Internet freedom in China has tightened once again, with Google's Gmail largely inaccessible for a fourth day.
Internet transparency monitor GreatFire.org reports the e-mail service is 84 percent blocked in the country after months of disruptions.
China has banned other Google products (like Picasa and YouTube) for years, but problems for Gmail users largely began in June, with the 25th anniversary of the Tiananmen Square crackdown on pro-democracy demonstrators.
Since then, GreatFire reports at least 15 days of blocked Gmail usage every month.
Initial reports of difficulty using the web-based email first emerged Friday. Google data shows a sharp drop in China's Gmail traffic beginning December 26.
China tightly controls the Internet using the so-called "Great Firewall" system that frequently targets foreign websites, including Facebook and Twitter.
Google says the problems accessing Gmail in China are not on the company's end.
When asked about the outage at a news conference on Monday, China's foreign ministry spokeswoman denied knowledge of the problem and deferred questions to another government agency.
"I don't have the knowledge about what you just mentioned. The Ministry of Foreign Affairs is not the competent authority in charge of this. Please check with the Internet Information Office," said Hua Chunying, Chinese Ministry of Foreign Affairs spokeswoman. "But what I can tell you is that China consistently welcomes and supports foreign investors in legally conducting business in China. We will continue to provide an open, transparent and good environment for foreign companies operating in China."
Freedom House, which assesses Internet freedom around the world, places the country near the bottom of its 2014 rankings due to obstacles to access, limits on content, and violations of user rights.