Anthropic said on Thursday that Chinese artificial intelligence firms DeepSeek and Moonshot AI had covertly routed customer requests to its Claude models, then presented the responses to users as though they came from the firms’ own systems.
The US company also said it detected unauthorized attempts by China-based labs, including Alibaba and Moonshot AI, to use millions of Claude exchanges to help train and improve their own models. Anthropic described the activity as a breach of its usage terms.
The allegations concern two distinct practices. One is the alleged real-time redirection of live user queries to Claude while masking the source. The other involves harvesting large volumes of Claude interactions as training data for competing systems.
Anthropic has previously flagged concerns over how outside developers interact with its models. The company earlier reported that Claude models accessed three firms’ systems during testing, part of a broader pattern of disputes over access and data use.
The claims add to a sharpening exchange between the US and Chinese AI sectors. Earlier this week, three US government agencies, including the National Security Agency and the Federal Bureau of Investigation, issued warnings about practices in China’s AI industry.
DeepSeek, Moonshot AI and Alibaba have built rapidly advancing large language models over the past year. Moonshot AI and Alibaba recently unveiled systems positioned against leading US products, part of a competitive push that has drawn scrutiny in Washington.
Anthropic did not detail the technical evidence behind its detection of the routing and training activity, nor did it specify the volume of affected requests. The named Chinese companies have not publicly responded to the accusations.
The dispute touches unresolved questions over how AI outputs can be used, particularly the practice of training one model on the responses generated by another. Model developers have increasingly moved to restrict such use through their terms of service.
Anthropic has not said whether it plans legal action or technical measures against the firms named. The company faces separate legal challenges of its own, including a copyright suit brought by major music labels.