The U.S. Securities and Exchange Commission (SEC) has asked Twitter Inc. to disclose its methodology on estimating spam accounts in a letter addressed to chief executive Parag Agrawal.

Twitter reiterated its June response to the SEC that spam accounts on its platform represent fewer than 5% of its total users.

"Twitter believes that it already adequately discloses the methodology that it uses in calculating these figures," the company said in a letter dated June 22 to the regulator, according to its filing on Wednesday.

During a company-wide meeting Wednesday, Agrawal moved to reassure employees, calling a whistleblower's accusations "foundationally, technically and historically inaccurate."

Twitter General Counsel Sean Edgett also told employees the company reached out proactively to various agencies around the world before the news broke.

Twitter's former security chief Peiter Zatko had said in a whistleblower complaint that the social media company misled federal regulators about its defenses against hackers and spam accounts.

The SEC letter to Agrawal and company-wide meeting come ahead of a highly watched legal showdown between Twitter and Elon Musk, who wants to back out of his deal to buy the company for $44 billion, arguing Twitter misled the billionaire about the number of bot and spam accounts on its platform.

In June, the SEC sent a letter to Musk asking for clarification over some of the tweets the billionaire sent about his $44 billion deal for Twitter.

Twitter's escalating fight with Musk to enforce his $44 billion deal to buy the social media platform was expected to attract the SEC's scrutiny over whether Musk misled the market during the course of the deal.

Twitter has asked a Delaware court to order the Tesla boss and world's richest person to complete the merger, setting in motion what promises to be one of the biggest legal showdowns in Wall Street history.

Musk has said he was terminating the deal because Twitter violated the agreement by failing to respond to requests for information regarding fake or spam accounts on the platform, which is fundamental to its business performance.

The two sides head to trial on Oct. 17.

• Whistleblower Complaint Claims Twitter Has Major Security Flaws