Anthropic’s most advanced artificial intelligence model used fake identities to try and deceive real people and plant malicious code during testing by Britain’s AI Security Institute (AISI) –– the latest example of an AI model going rogue.

Anthropic and OpenAI models were tested with lowered security guardrails in lab environments, but, in a first, were found to engage in “social engineering” to pressure a human approver while carrying out an unsanctioned task, the government research lab said.

“This is the first time AISI has seen deception of this severity that was targeted at a real person, unprompted, in the real world,” the institute said Tuesday. There has been no evidence of real-world harm, it added.

The “security incident” is the latest in a string of examples of advanced AI models engaging in unauthorized actions, events that have prompted growing calls for more government action to regulate artificial intelligence and even to slow its pace of development.

Both OpenAI and Anthropic reported their models escaping testing environments and hacking into other systems in late July. But unlike these earlier reported security breaches, the British institute explicitly gave the models internet access during its testing.