Elon Musk has subpoenaed the head of Saudi Arabia’s Public Investment Fund in litigation over a 2018 tweet claiming the Tesla chief had “funding secured” to take the electric carmaker private.

Tesla’s legal team served papers to an office administrator for PIF governor Yasir al-Rumayyan on December 19, according to court documents filed in California federal court on Tuesday. Musk’s team is seeking to have al-Rummayyan, who is also the chair of Saudi Aramco, testify at the trial, which is scheduled to start in San Francisco later this month.

Any eventual testimony from al-Rummayyan could focus on discussions the PIF had held with Musk before his “funding secured” pronouncement. The investors who brought the lawsuit claim Musk manipulated Tesla’s stock price when he tweeted in August 2018 that he had financing in place to take the electric carmaker private at a price of $420 per share. A deal never materialised.