Debate has been ongoing since the original bitcoin paper that outlined how the cryptocurrency would work was released in 2008.
A person or group of people called Satoshi Nakamoto are said to be behind it. But, to date, nobody knows who Nakamoto is.
In a post on blogging website Medium, Sahil Gupta, who is a former intern at Musk's space company SpaceX, theorized that "Satoshi is probably Elon."
Gupta, who was at SpaceX in 2015, according to his LinkedIn profile, said Musk could be behind bitcoin because of his deep understanding of economics and cryptography, grip on advanced coding languages, and the fact he is a "polymath".
The former intern said Musk probably wanted to create it because it was 2008 during the recession and may have been motivated to "solve the lack of trust in banks by creating a currency that doesn't need them." In the blog post, Gupta laid out other evidence he believes point to Musk as bitcoin's creator.
But Musk denied this was the case, even saying he has lost bitcoin that his friend gave him a few years ago.
The search for Nakomoto has been going on for years. In 2014, Newsweek said that the bitcoin creator was a 64-year-old Japanese-American living in California named Dorian Prentice Satoshi Nakamoto. And just last year, Australian entrepreneur Craig Wright claimed he was the founder, though this was called into doubt.