According to media reports, the former Twitter security chief Peiter Zatko has accused the short message service of serious deficiencies in data protection.
Twitter has given regulators misleading information about user accounts and countermeasures against hacker attacks, CNN and the Washington Post quoted from an 84-page report by Zatko on Tuesday.
The US company has exaggerated its protective measures.
Zatko warned his colleagues that half of the servers are outdated and vulnerable to attacks.
Twitter boss Parag Agrawal has denied the allegations against employees, a CNN reporter on the service reported, citing a memo.
The allegations are against the background of the legal dispute over the failed takeover of Twitter by Tesla boss Elon Musk.
He withdrew his $44 billion takeover bid in July.
Musk justified this with alleged violations by Twitter of the deal's agreements.
The trial is scheduled to begin on October 17.
Musk was initially unavailable for comment on Tuesday.