OpenAI has published emails from Elon Musk in an attempt to undermine his lawsuit that claims the company has strayed from its founding mission to serve as non-profit check on the threats of generative AI. 

Musk last week filed a lawsuit against the ChatGPT makers, a company he co-founded as a nonprofit mission, for seeking profit by entering into a $13 billion partnership with Microsoft and keeping the code for its newest generative AI products a secret.

In the emails published Tuesday night Musk appears to have supported OpenAI becoming a for-profit company in the early days of the venture. 

The publication of the emails marks a dramatic escalation in the feud between Musk and the company he left in 2018 after executive refused to be bought out by Tesla. 

In one email from the Tesla CEO to OpenAI's Sam Altman, dated November 2015, Musk said the company needed to raise much more than $100 million to 'avoid sounding hopeless.' 

In another email, parts of which have been redacted, from December 2018, Musk told Altman and other executives that OpenAI would not be relevant 'without a dramatic change in execution and resources.'

'This needs billions per year immediately or forget it,' Musk wrote.

'We're sad that it's come to this with someone whom we've deeply admired—someone who inspired us to aim higher, then told us we would fail, started a competitor, and then sued us when we started making meaningful progress towards OpenAI's mission without him,' the company wrote in a blog post containing the emails.