Elon Musk's lawyers subpoena head of Saudi Arabia's $620 billion wealth fund for Tesla 'funding secured' tweets case

• Investors are suing Elon Musk over an August 2018 tweet where he claimed he had "funding secured" to take Tesla private.

• Musk's lawyers have subpoenaed Saudi Arabia's top wealth manager to be a defense witness in the upcoming court case.

• Text messages disclosed in April showed Musk raging at Yasir Al-Rumayyan for not supporting his efforts to privatize Tesla.

Elon Musk's lawyers are trying to force Saudi Arabia's top wealth manager to testify in upcoming litigation over a now-infamous tweet in which the Tesla CEO said he was considering taking the EV manufacturer private.

Tesla's legal team subpoenaed Private Investment Fund governor Yasir al-Rumayyan on December 19, according to documents filed Tuesday – with a San Francisco court case set to start later this month.

Investors suing Musk say that the world's second-richest man manipulated Tesla's share price in 2018 when he claimed that he had "funding secured" to take the company private at $420 a share.

That deal never happened, with Tesla remaining publicly listed.

PIF is a sovereign wealth fund – meaning that it invests on behalf of Saudi Arabia's government. It manages around $620 billion worth of assets, according to its most recent annual report.

Musk has since claimed publicly and in court documents that he had a handshake deal for the fund to provide the necessary cash for Tesla to delist from the S&P 500.