Elon Musk has said he expects Saudi Arabia's sovereign wealth fund to provide the cash for his Tesla buyout plan, throwing into question his claims last week that funding for the deal was "secured" in a move likely to prompt scrutiny from US regulators.

The billionaire chief executive said he had been approached by the Saudi fund "multiple times about taking Tesla private", stretching back to the beginning of 2017 when it had first expressed interest "because of the important need to diversify away from oil".

He said, following the Saudi fund's decision to buy almost 5pc of Tesla stock, he had met with its managing director on July 31, who had "strongly expressed his support for funding a going private transaction for Tesla at this time".

"I understood from him that no other decision makers were needed and that they were eager to proceed. I left the July 31 meeting with no question that a deal with the Saudi sovereign fund could be closed, and that it was just a matter of getting the process moving. This is why I referred to 'funding secured' in the August 7 announcement."

Mr Musk said he was still in talks with the fund's managing director who had asked for additional details on how the company would be taken private, and "expressed support" for proceeding with the deal "subject to financial and other due diligence and their internal review process for obtaining approvals".