The US district court of northern California has granted a motion to subpoena the musicians Grimes (AKA Claire Boucher) and Azealia Banks in the ongoing lawsuit against Tesla founder Elon Musk brought by a group of the company’s shareholders.

Additional subpoenas will be served against the publications Business Insider, the New York Times and tech website Gizmodo. The subpoenas will instruct the parties to preserve certain documents, including Twitter and Instagram messages and other potential evidence relating to the lawsuit, which the filing argues are “highly subject to deletion”.

The parties have not been called upon to provide evidence in court, according to a report in Business Insider. Grimes, Banks and Musk have not commented on the news. The Guardian has contacted representatives for each party.

Tesla’s investors are suing the company and Musk in a class-action lawsuit. They claim that Musk made false and misleading statements when he tweeted, in August 2018, that he was considering taking the company private at $420 (£324) a share. The plaintiffs allege that the tweet affected shareholders as they falsely believed he had secured funding to take the company private. The tweet provoked an 11% surge in shares in the company.

Elon Musk in Beijing this month to meet Chinese premier Li Keqiang. Photograph: Mark Schiefelbein/AP

Musk attempted to justify the tweet, writing in a blogpost that the Saudi investment fund that owns 5% of Tesla had approached him several times over the last two years with offers of help. If investigators conclude Musk overstated the nature of the financing, it could form the basis for bringing a market manipulation case.

Last September, the US Securities and Exchange Commission charged Musk, 47, with misleading investors. The tweets had no basis in fact, and the ensuing market chaos hurt investors, regulators claimed. Tesla and Musk agreed to pay $20m each to the SEC and, under a settlement, the billionaire stepped down as the company’s chairman but remained as chief executive.

Grimes was in a relationship with Musk when he sent the tweet and had recently accompanied him on a trip to China. Banks claims she was staying at one of Musk’s Los Angeles properties at the time he posted the tweet, allegedly waiting for Grimes to participate in a planned collaboration.

Banks claimed that she saw Musk “scrounging for investors”. She also alleged that he was tweeting while on acid. Musk claimed he had never met Banks. The complaint says Banks “has proven to be a key source of information” in this matter.

‘Key source of information’ … Azealia Banks. Photograph: Jonny Weeks/The Guardian

“Ms Boucher and Ms Banks were in close contact with Mr Musk before and after the tweet and are believed to be in possession of relevant evidence concerning Mr Musk’s motives,” Adam M Apton, the lawyer representing the investors, told Business Insider earlier this month.

In late August, Banks apologised to Musk “for all of the painful events you’ve endured over the past week, as I feel as though my actions have largely exacerbated them”. However, in early January, Banks appeared to threaten Musk after the tech billionaire’s lawyers maligned the rapper’s credibility in a filing.

“They are still slighting me like I don’t have plenty more dirt to spill on Elon,” Banks wrote in an Instagram post that she later deleted. “This is going to get extremely ugly … Elon will learn very soon who is more powerful of us two.”