It was a bromance that saw two of the tech world’s titans speak about each other in glowingly appreciative terms over the years.

Elon Musk once tweeted that Twitter co-founder Jack Dorsey ‘has a good heart’.

Dorsey for his part has described the Tesla tycoon as someone who ‘cares deeply about our world’.

But things have taken a more serious turn with Musk trying to back out of a US$44bil takeover of Twitter - and he has formally issued Dorsey with a subpoena.

Dorsey has been asked for documents and communications relating to Musk’s agreement earlier this year to buy the site.

Musk has also requested material relating to spam accounts on the platform. That is at the heart of the reasons given by the Tesla boss for pulling out of the deal.

The 51-year-old’s lawyers said last month that Twitter had failed or refused to respond to multiple requests for information on how many of the users registered to the platform were fake or spam accounts.

That is a key metric in judging its business performance. Musk claimed Twitter was in ‘material breach’ of multiple provisions of the takeover deal. Twitter is suing Musk and has asked a judge in Delaware to order him to complete the deal. It has denied Musk's spam allegations. A five-day trial begins on Oct 17.

Musk has also subpoenaed Wall Street banks Goldman Sachs and JP Morgan over how they advised the company on the deal.

The Tesla boss - the world’s richest man because of his stake in the electric car firm - has been an enthusiastic user of Twitter over the years.

He has even been fined millions of dollars by US financial authorities over his use of the platform in talking about his company.

Most recently, he briefly stoked the hopes of Manchester United fans disillusioned with the club's ownership by suggesting he planned to buy it, before making clear he had been joking. His relationship with Dorsey seems to have been notably warmer than the mutual frostiness between some other tech tycoons such as Facebook’s Mark Zuckerberg and Apple’s Tim Cook. They are fans of cryptocurrencies such as bitcoin.

Dorsey, 45, quit as Twitter's chief executive in November and left the board in May. He remains in charge of Block, a payments company which he also co-founded, previously known as Square.

Musk has in the past rallied to Dorsey's defence. In 2020 during an attempt to unseat him as Twitter chief executive, Musk tweeted that he supported Dorsey, making his ‘good heart’ comment.

Dorsey returned the favour when it emerged that Musk had built up a big stake in the company, saying he was ‘really happy’ that the Tesla boss looked set to join the board. Musk initially accepted a seat before changing course and offering to buy the company.

That move was also endorsed by Dorsey, who tweeted: “Elon is the singular solution I trust. I trust his mission to extend the light of consciousness.”

But then Musk controversially said he was pulling out, leaving Dorsey caught in the crossfire between him and Twitter’s board.

The wrangle took a further twist yesterday when allegations by Twitter's former security chief Peiter Zatko emerged. The 51-year-old - who left the firm in January - claimed Twitter misled federal regulators about its defences against hackers and spam accounts, US media reported.

He is said to have filed a formal complaint with the Securities and Exchange Commission and the Department of Justice as well as the Federal Trade Commission.

A Twitter spokesman said: “Zatko’s allegations and opportunistic timing appear designed to capture attention and inflict harm on Twitter, its customers and its shareholders.”

 - TNS