Documents obtained from two data scientists employed by Musk showed they estimated in early July that the number of fake accounts on the platform at 5.3% and 11%, the Twitter lawyer told a Delaware judge.
"None of these analyses so far as we can tell remotely supported what Mr. Musk told Twitter and told the world in the termination letter," said the lawyer, Bradley Wilson.
Musk and his attorney did not immediately respond for a request for comment.
Musk and Twitter are locked in a court fight and Twitter is seeking an order directing Musk to close the deal at $54.20 per share. Twitter's stock ended Tuesday trading at $42.09, up 1.4%.
They are scheduled to go trial starting Oct. 17 in Wilmington, in Delaware's Court of Chancery.
Musk agreed in April to buy Twitter for $44 billion but within weeks was complaining the number of bot accounts was much higher than Twitter's estimate of less than 5% of users.
On July 8 Musk said the actual figure was "wildly higher" and that Twitter had misled him, allowing him to walk away without penalty from the deal.
Wilson brought up the report by data scientists during a hearing at which both parties were asking the judge to order the other side to turn over more messages or documents, the process known as discovery.
Also on Tuesday, a court notice said Musk's deposition was being rescheduled from this week to Oct. 6-7.
Musk's deposition is expected to be a key part of the litigation. In past testimony, he hasbeen combativeunder oath.
Brian Quinn, a professor at Boston College Law School, said that the timing of depositions matter, and Twitter might be better off delaying the interview of Musk until after they have obtained his communications.
"You're going delay your best witnesses for the end, as much as possible, so you have all the discovery," Quinn said.