A version of an artificial intelligence (AI) tool which the company said was too powerful to be released to the public has just been released to the public. Claude Fable 5 is a version of Anthropic's Claude Mythos, an AI program which caused serious concerns among technology, finance, and government leaders when it was released privately in April for previewing and testing.

Some worry the tool is so powerful it could pose financial security risks, though others have questioned how much of the hype is marketing spin. Anthropic said on Tuesday Fable will be released with safeguards and user limitations in place, though it said 'releasing a model this capable comes with risks.' 'Fable's capabilities exceed those of any model we've ever made generally available,' it added.

When Mythos was first released to a small group of organisations to preview the tool, Anthropic said it was doing so because the tool was so intelligent that it could be dangerous because of its ability to exploit or hack computer systems. Despite these warnings, US government agencies have been testing Mythos too. The company is expected to become a public company soon, as its private valuation has neared $1tn (£747bn).

The updated access was limited to a 'small group of cyberdefenders and infrastructure providers' but is expected to go beyond that soon. 'We intend to expand access to Mythos 5 through a broader trusted access program,' the company said.

Both Fable and Mythos, which are essentially the same model but with different safeguards and levels of access in place, can work 'unattended' on human commands that the tools are given for longer periods of time 'than any previous Claude models.' Anthropic co-founder Jack Clark last week told BBC Newsnight that the ability of AI tools was expanding so rapidly that the company thought there should be a way for the public to slow the technology's advancement.