BEIJING — A powerful artificial intelligence model that appeared anonymously on a developer platform last week was revealed yesterday to be from Chinese smartphone and EV giant Xiaomi, after it fuelled speculation that startup DeepSeek was quietly testing its next-generation system ahead of a launch.

The release of DeepSeek’s low-cost models DeepSeek-V3 and R1 triggered a global tech stock selloff last year, causing investors to question whether US AI firms needed to spend billions of dollars on AI computing power. Since then, there has been a great deal of interest in DeepSeek-V4, a next-generation model that has yet to be released.

The mysterious free model, called Hunter Alpha, surfaced on the AI gateway platform OpenRouter on March 11 without any developer attribution and was later described by the platform as a “stealth model.”

Xiaomi’s AI model team MiMo, run by former DeepSeek researcher Luo Fuli, yesterday said Hunter Alpha was an “early internal test build of MiMo-V2-Pro,” a model designed to serve as the “brain” of AI agents, tools that can allow users to execute complex tasks with fewer human prompts and supervision when compared with a chatbot.