President Joe Biden took aim at billionaire Elon Musk during a campaign event, following reports that the Tesla CEO may have illegally worked in the United States during the 1990s while on a student visa. The allegation, revealed in a Washington Post report, claims that Musk, who immigrated from South Africa, did not adhere to visa regulations when he arrived in the country. “That wealthiest man in the world turned out to be an illegal worker here. No, I’m serious. He was supposed to be in school when he came on a student visa. He wasn’t in school. He was violating the law. And he’s talking about all these illegals coming our way?” Biden said at a union hall event in Pittsburgh, drawing a stark contrast between Musk’s past and the entrepreneur’s current stance on immigration. The Washington Post report alleges that Musk arrived in Palo Alto, California, in 1995 with plans to attend Stanford University. However, instead of enrolling in courses, Musk focused on his startup, Zip2, reportedly violating the terms of his visa. Here's a look at Musk's contact with Putin and why it matters The newspaper, citing court documents and former associates, highlighted a 2005 email from Musk to his Tesla co-founders in which he allegedly acknowledged his lack of legal authorisation to remain in the US while starting his business. In response, Musk defended himself, stating on X, formerly Twitter, that he was “in fact allowed to work in the US” and referred to Biden as a “puppet” spreading falsehoods. The report suggests that Musk’s early investors were concerned about his visa status, fearing that he could face deportation. Musk allegedly applied to Stanford to secure a legal foothold in the US, but he instead prioritised building Zip2, which was eventually sold to Compaq in 1999. Musk, now the world’s richest person, has become a vocal supporter of the GOP, with over $70 million in donations to the campaign of Republican presidential nominee Donald Trump and other GOP candidates. Elon Musk promises daily $1 million award He has frequently echoed Trump’s anti-immigration rhetoric and is even touted for a potential role in a future Trump administration. Both Tesla and X have yet to respond to the recent allegations.