Elon Musk, who is trying to walk away from his deal to acquire Twitter Inc., is seeking documents from advertising technology firms as part of his quest to gain more information on bot and spam accounts on Twitter, according to filings in a Delaware court on Thursday.
Twitter sued the Tesla chief executive, who accused Twitter of hiding information about how it calculates the percentage of bots on the service, for trying to walk away from the $44 billion agreement. A trial is scheduled for October 17.
Musk's lawyers have been subpoenaed by both Integral Ad Science IAS and DoubleVerify for any documents or communications regarding their involvement in reviewing accounts or participation in any audit of Twitter's user base.
IAS and DoubleVerify, both of which are based in New York, use technology to verify that digital ads are seen by real people. Advertisers use the services to make sure ads are seen by potential customers and not automated bots.
IAS, DoubleVerify and Twitter didn't respond immediately to requests for comment.
In response to a question about how Twitter audits its service and also linked to a Reuters story on Musk targeting the ad firms, Musk stated that Twitter's daily active users are 65 million less than what the company has touted. Twitter stands by its disclosures.
Users who log onto Twitter from the website or apps are able to serve ads or used paid products like subscriptions, according to Twitter filings.