Some of WeChat's content, including articles on its public accounts page, was briefly searchable in the last few days on Alphabet-owned Google and Microsoft's Bing, but not on China's dominant search engine Baidu, Reuters checks showed.
The change had prompted speculation that Tencent was heeding a call by Chinese authorities for its tech giants to tear down "walled gardens" in the country's cyberspace which has come amid a wide ranging crackdown on the sector.
"Due to recent technological upgrades, the official accounts' robots protocol had loopholes, which caused the external crawlers to scrape part of the official accounts' content," Tencent said in a statement in Chinese.
"The loopholes have since been fixed."
Google, Microsoft, and Baidu did not immediately respond to a request for comment. Google is not available in China.
The ability to find WeChat content on Google and Bing was initially raised by users on developer forums. China's internet sector has been long dominated by a handful of technology giants who have historically blocked rivals' links as well as their search crawlers, a practice is often referred to as 'walled gardens'.
In recent months, this practice has been targeted by Chinese authorities as part of a sweeping regulatory crackdown.
Last month, China's Ministry of Industry and Information Technology (MIIT) ordered companies to stop blocking links, which they said has affected users' experience and damaged consumer rights.
The MIIT has also been studying plans and conducting research to make WeChat content available on external search engines, according to a person with direct knowledge.
MIIT did not immediately respond to requests for comment.
Some users on China's Twitter-like Weibo platform expressed dismay over Tencent's comments.
"This should be an important attempt of creating an open internet space, how can you call it a bug," said one user.
(Reporting by Yingzhi Yang and Brenda Goh; Editing by Jacqueline Wong and Kim Coghill)
By Yingzhi Yang and Brenda Goh