Elon Musk's review of Twitter accounts by his advisers did not back up the billionaire's allegation that the number of fake users was "wildly higher" than 5% as he claimed, a Twitter lawyer has told a US judge.

Social media giant Twitter and Mr Musk sparred in court, each digging for evidence to prevail in a high-stakes trial next month over the Tesla CEO's bid to break his buyout deal.

Mr Musk has been keen to find evidence to back his accusation that Twitter misled regulators and investors about what portion of accounts are actually spam or software "bots," as well as its key measures regarding growth.

Twitter, which has sued Mr Musk to force him to complete the €44 billion buyout deal, seeks material to prove he is contriving excuses to walk away because he changed his mind.

A Twitter attorney told the judge it was a struggle to get documents from the data scientists Mr Musk used to estimate the portion of fake accounts on the social network.

What they finally got did not back his accusation about it being much higher than 5%, attorney Brad Wilson said.

Mr Wilson contended that Twitter has encountered a "pattern of delay and obfuscation" when it comes to what Mr Musk learned from data scientists he had study Twitter data.

Lawyers for Mr Musk, in turn, pressed the judge to make Twitter hand over more messages or other material, particularly regarding "monetisable daily active users" and "user active minutes."

The hearing came during a discovery phase in which rival sides seek documents, emails, depositions and more to back their positions.

The long list of those called on to provide documents or to answer questions in the case includes Twitter co-founder and former chief Jack Dorsey.

Mr Musk will be under oath over the course of two days next week in sessions that are to be recorded by "stenographic, sound and visual means," according to a filing.

His deposition is set to take place privately in law offices ahead of a five-day trial scheduled to begin on 17 October in the Court of Chancery in the state of Delaware.

The deposition is expected to be a key part of the litigation.

The world's richest man said in a letter in April, later adding that accusations made in a whistleblower complaint by a former head of security at Twitter were part of his reasons for walking away from the deal.

Twitter has stood by its assessment of user numbers, and portrayed the whistleblower as a "disgruntled former employee" whose allegations are without merit.