Chaoyang district police announced the five-day detention on their Weibo account on Thursday after concluding an investigation into the stunt, which shocked attendees, stole the limelight from the company's latest AI announcements and sparked a social media frenzy in China, the South China Morning Post reported.
The billionaire was speaking about applications for Artificial Intelligence (AI) on Wednesday when the young man approached him and spilled the liquid over his head from a water bottle, Channel News Asia reported.
"What's your problem?" Li shouted in English. "There are many difficulties on the road to achieve AI, but it will not impact Baidu's determination," Li was quoted as saying.
The man was later taken away by security personnel. The incident took place during "Baidu Create 2019" a yearly gathering where the company shows off its advances in AI.
Baidu, also called China's Google, and Li have long been targets of public anger over perceived problems linked to searches in China.
The company faced a major public backlash in 2016 when a Chinese student died after seeking a medical treatment advertised on its search pages.
China's biggest search engine site was widely criticised in June for promoting its own results and low-quality articles on Baijiahao the firm's news aggregation platform which publishes content from other sites over news from other channels, reports TechNode.
The firm has been struggling to regain users' trust after a series of scandals over the past few years.
( With inputs from IANS )