According to the letter, Musk has been requesting the information since 9 May, a month after first making his offer to buy the company, in order to determine how many of the company's 229 million accounts are false.
Musk's purchase was been put on hold "temporarily" last month, due to the company's spam user calculations.
"Twitter deal temporarily on hold pending details supporting calculation that spam/fake accounts do indeed represent less than 5% of users,” Musk tweeted at the time.
His tweet included a link to a report from earlier this month that stated that spam and false accounts account for less than 5% of Twitter's daily users.
Here is everything you need to know about it.
How much did Musk pay to buy Twitter?
Musk has stated that he believes the site needs to alter in order to grow and better encourage free speech.
The financing comes from Morgan Stanley and other financial institutions - other banks involved include Barclays, Bank of America, Societe Generale, Mizuho Bank, BNP Paribas, and MUFG.
Morgan Stanley is one of Twitter’s biggest shareholders, behind Vanguard Group and Musk.
Musk said that 13 billion dollars (£10 billion) in financing came from Morgan Stanley and the other banks, as much as $12.5 billion dollars (£9.6 billion) would be loans secured by his Tesla stock, and committed $21 billion dollars (£16 billion) in equity, “directly or indirectly” from him, although he did not say what the source of those funds would be.
Musk is the world’s wealthiest man, according to Forbes, with a nearly $279 billion (£214 billion) fortune.
But Musk’s actions since buying a 9% stake in Twitter have also been described by one expert as a demonstration that he should not be given control of the company.
Mike Rhodes, chief executive of mobile marketing firm ConsultMyApp, said: “It would be plain ridiculous for Twitter to accept this offer and place itself in the hands of someone who has demonstrated his sporadic nature in the past two weeks.”
Why does Musk want to buy Twitter?
In April, alongside the announcement that Musk had bought a 9% stake in Twitter, it was also revealed he would join the board of directors.
But just days later, Twitter chief executive Parag Agrawal confirmed that Musk had changed his mind.
Musk has said he believes changes are needed in order to help the site thrive and better support free speech.
In a statament released following the confirmtion of his accepted bid, Musk said: “Free speech is the bedrock of a functioning democracy, and Twitter is the digital town square where matters vital to the future of humanity are debated.
“Twitter has tremendous potential - I look forward to working with the company and the community of users to unlock it.”
Who previously owned Twitter?
There are many stockholders in Twitter Inc., therefore no single person owns the entire corporation.
It's a 'public' firm because its shares are accessible for everyone to buy on the stock exchange, whereas it would be a 'private' company if only a few people or groups owned it.
According to the Wall Street Journal, the group with the largest stake is Vanguard Group, an American investment firm that is one of the world's largest.
Vanguard Group is thought to own 82.4 million shares of the corporation, or 10.3% of the company, as of 15 April.
Musk is the company's second-largest stakeholder. He owns 9.2% of Twitter Inc. with his 73.5 million shares.
The remaining shares are held by a variety of financial institutions, including Morgan Stanley and BlackRock Inc.
Jack Dorsey, the original co-founder and former CEO of Twitter, presently owns 2.25% of the company.
What will Elon Musk’s Twitter look like?
Musk is well known for his belief in absolute free speech and has suggested he does not think Twitter is living up to its principles on the issue.
But a change of Twitter policy instigated by Musk to loosen rules around speech on the site could create more problems for the company in an age of increasingly polarised online discourse.
In his statement, he said: “I [also] want to make Twitter better than ever by enhancing the product with new features, making the algorithms open source to increase trust, defeating the spam bots, and authenticating all humans.”
One expert said that Musk’s own history of tweeting could hamper the delicate balancing act of content moderation Twitter is currently engaged in.
“Sowing the seeds of championing ‘free speech’ is one thing, but let’s not forget Elon’s view of simply voicing opinion has been seen as reckless by regulators in the past,” Dan Lane, senior analyst at investment and stock trading app Freetrade, said.
Musk has previously run into problems with US regulators at the Securities and Exchange Commission (SEC) over his own tweets, having been accused of breaching trading rules when tweeting about his business interests.
He has also been accused of tweeting misinformation about Covid-19 after posting in March 2020 that children were “essentially immune” to the disease.
Musk’s attitude to free speech is shared by the likes of Donald Trump and a number of other right-wing political figures who have had their accounts suspended for violating Twitter content rules but claim they have been the victims of censorship.
Some believe a Musk takeover could mean a return to the platform for Trump and others, but reinstating those users would be a highly controversial move and could bring further scrutiny to the company and its approach to moderation.
Infamously, British cave explorer Vernon Unsworth sued the Tesla co-founder after he called him “pedo guy” and “sus” (suspicious) on Twitter in a spat following the July 2018 Thai cave rescue.
Unsworth lost the case after Musk’s lawyers argued it was no more than a playground insult and did not represent an allegation of paedophilia, to which a jury agreed.