By Kashmira Konduparty
Anthropic, the artificial intelligence company has accused Alibaba, the Chinese technology giant of conducting a large-scale effort to extract capabilities from its Claude AI models, describing the incident as the largest known “distillation” attack against the company to date.
According to a letter reviewed by Reuters, Anthropic alleged that operators affiliated with Alibaba and its AI research division, Qwen, used thousands of fraudulent accounts to interact with Claude and harvest information that could be used to improve competing AI systems. Anthropic said the activity took place between April 22 and June 5 and involved more than 28.8 million exchanges with Claude through nearly 25,000 fake accounts.
READ: Pentagon names Alibaba and BYD as companies aiding Chinese military (June 9, 2026)
The company described the effort as a “distillation” campaign, a process in which developers use the outputs of a more advanced AI model to train a less capable one. While distillation is a common technique within AI development when performed on a company’s own systems, Anthropic argued that the alleged activity constituted unauthorized extraction of intellectual property.
“These distillation attacks are carried out illicitly, systematically, and at industrial scale,” Anthropic wrote in the letter, according to the report. The company said the campaign targeted some of Claude’s most valuable capabilities, including software engineering, advanced reasoning and long-duration task management.
Anthropic further alleged that the operation was intended to accelerate the development of Alibaba’s AI models, particularly those produced by its Qwen laboratory. The company warned U.S. lawmakers that such efforts could allow Chinese AI developers to replicate advanced American AI capabilities without incurring the substantial research and development costs required to build them independently.
READ: Anthropic CEO Dario Amodei calls India’s AI Summit ‘disorganized’ (June 19, 2026)
The accusations come amid growing competition between U.S. and Chinese technology firms in the race to develop increasingly powerful artificial intelligence systems. Anthropic has previously alleged that other Chinese AI companies, including DeepSeek, Moonshot AI and MiniMax, improperly used Claude to improve their own models.
The dispute also unfolds against a backdrop of increasing U.S. restrictions on advanced AI technologies. Earlier this month, the U.S. government ordered Anthropic to suspend foreign access to some of its most advanced AI models, citing national security concerns.
The allegations are likely to add to tensions between Washington and Beijing over artificial intelligence, intellectual property protection and technological leadership.