Sept 13 (Reuters) – Disclosures by a former Twitter Inc ( TWTR.N ) executive turned whistleblower show that at least one Chinese agent is working at the company, Senator Chuck Grassley said in opening remarks during a Senate hearing on Tuesday , with a deposition from the informant. Peiter “Mudge” Zatko, a famous hacker who served as Twitter’s security chief until he was fired last year, said during the hearing that some Twitter employees were concerned that the Chinese government could collect data on the company’s users. It was cited in a Reuters story on Tuesday that detailed infighting between some groups that wanted to maximize the ad revenue opportunity from Chinese advertisers and others worried about doing business inside China amid rising geopolitical tensions. read more Sign up now for FREE unlimited access to Reuters.comSign up “In short, if we were already in bed, it would be problematic if we lost that revenue stream,” Zatko said. “His disclosures also note that the FBI informed Twitter of at least one Chinese agent at the company,” Grassley said in his opening statement. Grassley noted that Twitter CEO Parag Agrawal declined to appear at the hearing, fearing it could jeopardize the company’s legal battle against Elon Musk, who is also the chief executive of Tesla ( TSLA.O ) . Twitter and Musk are headed to trial next month over whether the $44 billion takeover deal should go through. Later on Tuesday, Twitter will also announce the results of a shareholder vote on Musk’s takeover of the company. A majority of shareholders have already approved the deal, sources told Reuters. read more The San Francisco-based company sued Musk for terminating the deal, while the Tesla CEO countered, accusing Twitter of misrepresenting the number of fake and spammy accounts on its service. A Delaware judge ruled last week that Musk can include Zatko’s whistleblower claims in his lawsuit against Twitter, but denied his request to delay the trial. read more The Senate Judiciary Committee is questioning Zatko over his allegations that Twitter misled regulators about its compliance with a 2011 settlement with the Federal Trade Commission over improper handling of user data. Since then, Twitter has made “little meaningful progress on its core security, integrity and privacy systems,” said Zatko’s complaint filed with regulators in July. The committee, chaired by US Senator Dick Durban, is also expected to press Zatko over his claim that one or more of Twitter’s employees were working on behalf of foreign governments. Durbin, speaking to reporters on Monday, said Zatko’s allegations were “a matter of grave personal concern and privacy.” Twitter said Zatko was fired for “ineffective leadership and poor performance” and that his allegations appeared to be intended to harm Twitter. Zatko’s whistleblowing complaint appeared to contain more than two pages with links to supporting documents, including emails between Zatko and Twitter CEO Parag Agrawal and an assessment of misinformation and disinformation on Twitter. The number of documents was limited compared to Facebook whistleblower Frances Haugen, who released thousands of pages of internal material. Sign up now for FREE unlimited access to Reuters.comSign up Reporting by Sheila Dang in Dallas. additional reporting by Richard Cowan and David Shepardson in Washington; Edited by Cynthia Osterman, Nick Zieminski and Lisa Shumaker Our Standards: The Thomson Reuters Trust Principles.