Manchester United fans might have got their hopes up over a new billionaire owner, but it would seem the chances of Elon Musk investing in the club are slim.

South African-born American businessman Musk, who among his many ventures is the founder of SpaceX and chief executive of Tesla, caused a stir on Tuesday by claiming he was going to buy United.

The club's fanbase have long wanted its current owners, the Glazer family, who also own the Tampa Bay Buccaneers, to sell up, with many supporters and pundits blaming the team's failures in the post Alex Ferguson era on sub-par investment.

Just three days after United suffered a humbling 4-0 defeat at Brentford, Musk wrote on Twitter: "I'm buying Manchester United ur [you're] welcome."

In the wake of Musk's first tweet, United's share price spiked by close to 17 per cent before settling slightly after the US pre-market trade.

Yet when asked if he seriously intended to purchase United, Musk responded: "No, this is a long-running joke on Twitter. I'm not buying any sports teams."

However, Musk did not fully close the door.

"Although, if it were any team, it would be Man U," the 51-year-old went on to write. "They were my fav team as a kid."