Anthropic Refuses to Grant UK AI Safety Agency Access to Test Latest Models

According to Sina Finance, Anthropic has refused to submit its latest model, Claude Mythos 5.1, to the UK Artificial Intelligence Safety Institute (AISI) for testing prior to release, restricting access solely to vetted U.S. institutions. This move has raised concerns within Whitehall and at AISI itself, with UK national security officials worried it could set a precedent that prevents AISI from accessing cutting-edge models in the future. Analysts point out that this action may be tied to the U.S. government's increasingly stringent export control policies regarding the AI industry—the U.S. government had previously implemented export controls on Anthropic's Mythos and Fable models, banning their use by foreign nationals. Anthropic declined to comment, stating only that it is "coordinating with the U.S. government to promptly expand model accessibility for more domestic and international partners."