China Probes DeepSeek and Moonshot Over Alleged Data Leaks to Anthropic's Claude

In brief

• China's Cyberspace Administration summoned all seven companies named in Anthropic's September 10 report before narrowing its probe to DeepSeek and Moonshot specifically.
• Anthropic alleges Moonshot routed more than 23 million exchanges to Claude through 5,380 fraudulent accounts, while DeepSeek generated more than 12.1 million exchanges in a 14-day window in July.
• The timing is awkward for both firms: DeepSeek is briefing the UN Security Council on AI risks this week, and Moonshot just filed confidentially for a $3 billion Hong Kong IPO.

China is turning Anthropic's own leak-detection playbook back on two of its most prominent AI labs.

The Cyberspace Administration of China has opened an investigation into DeepSeek and Moonshot AI over claims that both companies secretly routed sensitive user data to Anthropic's servers, The Information reported Tuesday, citing people familiar with the matter.

Officials reportedly visited the offices of both companies to interview executives and staff. Regulators want to know whether sensitive police, military, and state-linked corporate data ended up on U.S. servers.

For most of 2026, Anthropic has accused Chinese labs of stealing Claude's outputs to train cheaper rivals. The company even claimed these startups were rerouting their queries to Anthropic, essentially giving users Claude answers at a fraction of the price.