San Francisco, May 18 : After Elon Musk publicly reduced his earlier claim of $100 million donation to ChatGPT developer OpenAI to $50 million, another report has now revealed that only around $15 million of donations can actually be traced back to the Tesla CEO. Musk tried to take control of OpenAI in early 2018 but Sam Altman and OpenAI's other founders rejected Musk's proposal. The outgoing Twitter CEO, in turn, walked away from the company and reneged on a $1 billion planned donation, according to reports. Musk always claimed he donated $100 million to the ChatGPT developer, now backed by Microsoft. "I'm still confused as to how a non-profit to which I donated $100 million somehow became a $30 billion market cap for-profit. If this is legal, why doesn't everyone do it?" he tweeted in mid-March. A week later he posted again: "I donated the first $100 million to OpenAI when it was a non-profit, but have no ownership or control." In an CNBC interview on Tuesday, Musk strangely reduced his claim regarding the OpenAI donation, saying: "I'm not sure the exact number but it's some number on the order of $50 million." However, a TechCrunch investigation into the funding behind OpenAI, citing documents filed with the IRS and a state regulator, has revealed that Musk could not have given the company the $100 million he always claimed. "In fact, while the source of much of OpenAI's funding remains unclear, filings contain only around $15 million of donations that can be traced definitively back to Musk," the report said on Wednesday. Musk's lawyer did not respond to the report. In 2016, the Musk Foundation made a $10 million donation to yet another non-profit associated with Altman, called YC.org. YC.org, in turn, made a $10 million donation to OpenAI. That $10 million donation remains the only publicly disclosed cash contribution from Musk to OpenAI. YC subsequently gave OpenAI another $16 million in 2017, of which at least $5 million was likely Musk's, according to the report. Microsoft later invested around $1 billion in OpenAI. /IANS